New Science at the American Astronomical Society Meeting

4 February 20156 March 2015 / raminskibba / Leave a comment

I’d just like to summarize some of the exciting new scientific results presented at the American Astronomical Society meeting in Seattle last month. I think it will be interesting to those of you science lovers who’re wondering what all the hubbub was about and for you astronomers who weren’t able to make it.

This is my third and final post in a series about the AAS meeting. The first two dealt with science policy, and diversity and sustainability. As I mentioned in a previous post, I enjoyed attending as both a scientist and science writer, and I was happy to personally meet the journalists writing excellent stories about the meeting (some of which I’ve linked to below).

I’ll start with some special sessions and other sessions focused on interesting science that included results I hadn’t seen before, and then I’ll end with some interesting plenary talks given by great speakers. It was a busy meeting and many of the sessions ran in parallel, so it’s inevitable that I missed some things and that this summary is incomplete. (Plus, I’m usually drawn to the sessions about galaxies, dark matter, and cosmology, and I often miss the other ones.) If you know of interesting announcements or talks that I missed here, you’re welcome to comment on them below.

Sloan Digital Sky Survey (SDSS)

After 15 years of great science, it was exciting to see the SDSS have its final public data release—until SDSS-IV data eventually come out, that is. At the press conference, Michael Wood-Vasey gave an overview, Constance Rockosi spoke about the data release, Daniel Eisenstein spoke about the Baryon Oscillation Spectroscopic Survey (BOSS), Jian Ge spoke about the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS), and Steven Majewski spoke about the APO Galactic Evolution Experiment (APOGEE). According to Rockosi, more than 6,000 papers have been published using publicly released SDSS data. The SDSS has observed tens of thousands of stars, hundreds of thousands of quasars, and millions of galaxies.

In addition, members of the BOSS collaboration presented (nearly) final results at a session dedicated to the survey. If you’re interested, check out this article I wrote about it for Universe Today. (Thanks to Nancy Atkinson for editing assistance.)

Distribution of galaxies in a slice of the BOSS survey. (Courtesy: SDSS-III)

3D-HST

Researchers presented newly published results and interesting work-in-progress about the evolution of distant galaxies using spectroscopic data from the 3D-HST survey, which is led by Pieter van Dokkum (Yale Univ.) and Ivelina Momcheva (Carnegie Observatories), combined with imaging data from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS), taking advantage of instruments aboard the Hubble Space Telescope. The figure below shows the spectral features of tens of thousands of galaxies, which indicate star formation activity, active galactic nuclei activity, and stellar age. If you’re interested, I wrote an article about some of these results for Sky & Telescope. (Thanks to Monica Young for editing assistance.)

Spectral features of high-redshift galaxies. (Courtesy: Gabriel Brammer, 3D-HST)

Andromeda Galaxy

In a session dedicated to Andromeda—known as M31 by astronomers—as well as in other related sessions, research scientists and Ph.D. students presented studies about the stars, globular clusters, molecular clouds, dust, structure, dynamics, surface brightness profile, and stellar halo of the galaxy. The continued interest in our fascinating neighbor is understandable; Andromeda’s only 2.5 million light-years away from our galaxy! Like our Milky Way, Andromeda is a spiral galaxy, and it’s the most massive galaxy in the Local Group.

Many of these AAS results came from the Panchromatic Hubble Andromeda Treasury (PHAT) Survey, which is led by Julianne Dalcanton (Univ. of Washington), who presented highlights in a press conference as well. Dalcanton and her colleagues released this PHAT panoramic image of the galaxy below, and it received well-deserved press attention, including in NBC and Sky & Telescope.

Map of Andromeda galaxy. (Courtesy: HST, PHAT)

Exoplanets

Many people were understandably excited about extra-solar planets, or exoplanets, detected by scientists with NASA’s Kepler space telescope. Every day of the meeting included talks and posters about the masses, abundances, dynamics, compositions and other properties of exoplanets as well as those of stars and supernova remnants examined with Kepler. In addition, astronomers’ announcement that they now have more than 1,000 confirmed exoplanets with Kepler and follow-up observations garnered considerable media attention (including these articles in Nature, BBC, and New York Times). They have at least 3,000 more planet candidates, and they will surely identify many more as Kepler continues its mission through 2016.

Of course, astronomers seek to find as many as possible Earth-like planets in or near the habitable regions orbiting Sun-like stars (often referred to as the “Goldilocks” zone). When these are successfully identified, the next step is to characterize their properties and try to assess the likelihood of life forming on them. Astronomers have found at least eight Earth-size planets in the habitable zone, including two of the newly announced ones, Kepler-438b and Kepler-442b. They also released these cool old-school travel posters. If you have a space ship that can travel 500 light-years a reasonable time, you should check out 186f on your next vacation!

Kepler’s alien planet travel posters. (Courtesy: NASA)

“Pillars of Creation”

On the 25th anniversary of the launch of the Hubble Space Telescope, astronomers released new images of the iconic star-forming region in the Eagle Nebula in the Serpens Cauda constellation, known as the “pillars of creation.” Journalists at Slate, CBS, and elsewhere shared these amazing images. At first I thought not much science was done with them, but by combining observations at visible and infrared wavelengths, astronomers can investigate what’s happening with the cold gas clouds and dust grains and assess how rapidly new stars are forming and where. For more, you can also see Hubble’s press release, which coincided with the press conference on the first day of the meeting.

Image of “pillars of creation.” (Courtesy: NASA and ESA)

Other Results

I saw many other interesting talks and posters at the meeting, but I don’t have the time/space to get into them here. On galaxies and the large-scale structure of the universe (which I’m interested in), I saw talks involving modeling and measurements with the Galaxy And Mass Assembly (GAMA) survey, the Six-degree Field Galaxy Survey (6dF), and I presented research using the PRIsm MUlti-object Survey (PRIMUS). But the SDSS dominated the field.

In addition, Joss Bland-Hawthorn, Sarah Martell, and Dan Zucker presented some impressive early science results from the GALactic Archaeology with HERMES (GALAH) survey of the Milky Way, which uses an instrument with the Anglo-Australian Telescope. (GALAH is named after an Australian bird.) Astronomers combine GALAH observations with astrometry from Gaia and over the survey’s duration will produce detailed data for 1 million stars in our galaxy! In particular, they utilize a technique called “chemical tagging” to study the abundances of at least 15 chemical elements for each star, allowing for studies of stellar dynamics and merger events from infalling “satellite” galaxies. I look forward to seeing more results as they continue to take data and analyze them; their first public data release is planned for 2016.

PLENARY SESSIONS

I’ll briefly describe a couple of the plenary talks below, but I missed a few others that sounded like they could be interesting, including “The Discovery of High Energy Astrophysical Neutrinos” (Kara Hoffman); “Gaia – ESA’s Galactic Census Mission” (Gerry Gilmore); and “The Interactions of Exoplanets with their Parent Stars” (Katja Poppenhaeger).

Also, Paul Weissman (JPL/Caltech) gave an overview of the Rosetta mission and the comet C-G/67P, and Al Wootten (NRAO) gave an overview of many recent science papers using the Atacama Large Millimeter Array (ALMA). Rosetta and its lander Philae has run a few experiments already, and scientists with the mission have found that the bulk density of the nucleus is less than half the density of water ice and that its D/H ratio is different than the abundance ratio of the Earth’s oceans. More recently, Rosetta detected a crack in the “neck” of the comet, and they’ve abandoned an idea for a close flyby search for the lost lander, which might wake up in a few months when it receives more solar power. And if you’re interested in ALMA science, such as involving the gas kinematics of protostars and protoplanetary disks and the gas and dust clouds of distant galaxies, watch for proceedings from their recent Tokyo meeting, which are due to be published next month.

Cosmology Results from Planck

Martin White (UC Berkeley) gave an excellent talk about cosmological results from the Planck telescope, which he described as having the “weight of a heavy hippo and the height of a small giraffe.” Based on analyses of the power spectrum of the cosmic microwave background (CMB) radiation, so far it seems that the standard model of cold dark matter plus a cosmological constant (ΛCDM) is still a very good fit. Scientists in the collaboration are obtaining tighter constraints than before, and the universe still appears very flat (no curvature). They are planning a second data release this year, including more simulations to assess systematic uncertainties and more precise gravitational lensing measurements. White ended by saying, “I can explain to you what really well, but I can’t tell you why at all.”

White also hinted at, but didn’t reveal anything about, the joint analysis by Planck and BICEP2 astrophysicists. That analysis was completed recently, and now it seems that the detected polarization signal might be at best a mixture of primordial gravitational waves produced by inflation and of Milky Way dust, and they’ve obtained only an upper limit on the tensor-to-scalar ratio. Check out my recent article in Universe Today about this controversy.

Courtesy: ESA

Inflation and Parallel Universes

Max Tegmark (MIT) has talked and written about both inflation and the multiverse for many years, such as in a 2003 cover article and a recent blog post for Scientific American and in his book, “Our Mathematical Universe.” From the way he presented the talk, it was clear that he has discussed and debated these issues many times before.

Tegmark began by explaining models of inflation. According to inflation, the universe expanded for a brief period at an exponential rate 10^-36 seconds after the Big Bang, and the theory could explain why the universe appears to have no overall curvature, why it approximately appears the same in all directions, and why it has structures of galaxies in it. In one entertaining slide, he even compared the expansion rate of a universe to that of a fetus and baby, but then he said, “if the baby kept expanding at that rate, you’d have a very unhappy mommy.”

Expansion rates of a baby (human) and a baby universe

He subtitled his talk, “Science or Science Fiction?”, and that question certainly came up. Tegmark argued that inflation seems to imply at least some levels of a multiverse (see his slide below), which makes many astrophysicists (including me) nervous and skeptical, partly because parallel universes aren’t exactly testable predictions. But he made the point that some general relativity predictions, such as about what happens in the center of a black hole, aren’t testable yet we accept that theory today. He discussed “modus ponens” arguments: once we accept “if p then q,” then if p is asserted, we must accept q, whether we like it or not. In other words, if inflation generally predicts parallel universes and if we accept inflationary theory, then we must accept its implications about parallel universes. This is an important issue, and it’s another reason why BICEP2 and Planck scientists are trying to resolve the controversy about polarization in the CMB.

Predictions of different levels of the multiverse.

The Dark and Light Side of Galaxy Formation

Finally, in another interesting talk, Piero Madau (UC Santa Cruz), who was recently awarded the Heineman Prize for Astrophysics, spoke about galaxy formation and dark matter. In particular, he spoke about difficulties and problems astrophysicists have encountered while attempting to model and simulate galaxies forming while assuming a cold dark matter (CDM) universe. For example, he described: the cusp-core controversy about the inner profiles of dark matter clumps and galaxy groups; the problem of angular momentum, which is conserved by dark matter but not gas and stars; the missing satellites problem, in which more simulated dark matter subclumps (“subhaloes”) than observed satellite galaxies are found; and the “too-big-to-fail” problem, such that simulated subhaloes are much more dense than the galaxies we see around the Milky Way. These problems motivated astrophysicists to rethink assumptions about how galaxies form and to consider warm or self-interacting dark matter.

Madau ended by saying that evidence that the universe conforms to expectations of the CDM model is “compelling but not definitive,” and warm dark matter remains a possibility. Considering all of the exciting work being done in this field, this could be “the DM decade”…but then he said people have been talking of a DM decade for the past thirty years.

Science Policy at the American Astronomical Society: NASA, National Science Foundation, New Telescopes

23 January 201526 January 2015 / raminskibba / 3 Comments

Following my previous post, here I’ll write about some science policy-related talks, events, and news at the American Astronomical Society meeting two weeks ago.

National Aeronautics and Space Administration (NASA)

As we saw in President Obama’s State of the Union address on Tuesday, NASA’s sending Scott Kelly to join Mikhail Kornienko for a 1-year mission at the International Space Station, where they and their crewmates will carry out numerous research experiments and work on technology development. This could help toward sending manned missions to Mars in the future, which would involve much longer periods in space. Of course, actually getting to Mars involves many other challenges too; and let’s remember that the ISS has an orbit height of about 431 km while the closest distance between Earth and Mars is 54.6 million km–about 100,000 times further away. Reaching Mars is clearly an ambitious goal, but it’s achievable in the long term. (For SOTU coverage, check out these articles in Science and Universe Today.) The new budget extends the life of the ISS until at least 2024, “which is essential to achieving the goals of sending humans to deep space destinations and returning benefits to humanity through research and technology development.” The ISS accounts for most of NASA’s space operations budget, but that only accounts for a few percent of NASA’s total budget, which includes many other activities and missions.

The NASA Town Hall began with with an update on its budget for 2015, and if you’re interested in the details, take a look at my previous post. One important change is that education will not take up 1% of every project as before; instead, the new budget requires that educational activities be centralized in the Science Mission Directorate (SMD).

The National Academies, which include the National Academy of Sciences, organize a massive effort every decade for leaders in the astronomy and astrophysics community to prioritize their goals and challenges and to make recommendations about what kinds of large-, medium-, and small-scale projects should have funding and resources invested in them. The Decadal Survey for 2010-2020, “New Worlds, New Horizons in Astronomy and Astrophysics”, is detailed and well-organized, and you can view it online. It’s complementary to the European Space Agency’s (ESA) “Cosmic Visions” programme for 2015-2025. Astronomers have produced these surveys since the 1970s, and other fields are catching on too; for example, the 2015-2025 decadal survey of ocean sciences just came out today.

The NASA spokesperson pointed out that previous Decadal Survey missions—Hubble, Chandra, and Spitzer—have now become household names, and the James Webb Space Telescope and Wide Field Infrared Survey Telescope will too. JWST will be great for astronomy and for outreach, but it is nonetheless extremely expensive and over budget, which implies that some smaller projects won’t be funded. According to this detailed article by Lee Billings, JWST is taking an ever-increasing fraction of NASA’s astrophysics budget, and based on the presentation at the town hall, it looks like that will continue for the next few years. In the meantime, WFIRST’s budget will start ramping up soon too.

In other news, at the AAS meeting we also heard updates about research grants in 2014 through NASA’s funding of Research Opportunities in Space and Earth Sciences (ROSES) funding. The Astrophysics Data Analysis Program (ADAP) was funded at $7.5M last year with a 21% proposal success rate, and the Astrophysics Theory Program (ATP) was funded at $3.5M with a 11% success rate. I didn’t catch the stats for the other programs, such as those involving exoplanet research and instrumentation. Grant funding levels have been pretty flat for the past four fiscal years, but because of the increasing number proposals, the selection rate keeps decreasing. Theoretical astrophysicists will be dismayed that no ATP proposals will be solicited in 2015, but they say that there has been no reduction in funding, just a delay.

There were also interesting sessions about education and public outreach (E/PO) and Program Analysis Groups (PAGs) too, and I suggest checking out those links if you want more information and resources.

National Science Foundation (NSF)

I also attended the NSF town hall, and similar to the NASA one, was primarily about budget issues. The NSF budget fared alright for fiscal year 2015 and appears to be between the pessimistic and optimistic scenarios they envisioned. NSF is pursuing partnerships with universities, other institutions, and federal agencies on some projects, such as a NASA-NSF partnership on exoplanet research. NSF analysts expect an approximately flat budget out to 2019, but that could change. They’re already preparing for FY 2016, and the President’s Budget Request will come out in the near future.

For the division of astronomical sciences (AST), NSF research grant proposals had a success rate of 15-16% for both 2013 and 2014. Nonetheless, as with NASA, there appears to be a long-term decreasing trend; in 2002, the success rate was 38%. And as with NASA, this is mostly due to increasing numbers of proposals, and they’re starting to restrict the number of proposals submitted per investigator and per institution. They’re also developing strategies in case success rates drop below 10%, which would be a dire situation. I’ve been funded by NSF grants myself, and it’s stressful for faculty, research scientists, and grad students when proposals are rejected so often.

The NSF spokesperson briefly mentioned NSF “rotator” positions, which are temporary program directors who work at the NSF and collaborate with many people on a variety of policy and budget issues. The astronomical sciences has such a program, and if you want more information about it, look here.

The NSF also funds major telescopes, including the Atacama Large Millimeter Array (ALMA) in Chile, the Daniel K. Inouye Solar Telescope (DKIST) in Hawaii, and the Large Synoptic Survey Telescope (LSST), also in Chile. As you may know, scientists are making progress with ALMA and have obtained interesting results already (see below). DKIST is under construction, and construction will begin on LSST later this year. In NSF’s budget, existing facilities account for about 1/3 of it, individual and mid-scale programs are another third, and the rest of the budget goes to ALMA, DKIST, and LSST.

AAS Science Policy & Advocacy

Joel Parriott, the AAS’s director of public policy, and Josh Shiode, the public policy fellow, organized a great session on science policy and the AAS’s advocacy efforts. They gave an informative presentation about how budgets are determined and about the current budget situation for basic and applied research in the astronomical sciences. I didn’t know that the US currently funds 37% of the world’s R&D, but China is expected to overtake the US in the early 2020s.

Shiode also spoke about the importance of cross-cultural communication between scientists and policy-makers. As a scientist and as a constituent, there are many ways that you can influence your Congress members, and nothing beats interacting with them in person. If you’re an astronomer, I strongly encourage you to participate in the Congressional Visits Day. I participated in it last year (see my blog post about it), and I really enjoyed it. You can find more information here, and note the deadline on 3 February.

There are other ways to get involves as well. You can also call or write to your Representative or Senators as well as write letters to the editor or op-eds for your local newspaper. Note that some Congress members will be receptive to different messages or to different ways of framing scientists’ and educators’ concerns. One concern scientists have these days is that some members of Congress are interfering with the peer-review process in the NSF and NIH.

Telescopes

The AAS meeting also included a session on ALMA, a Thirty Meter Telescope (TMT) open house, and a JWST town hall, as well as one for Hubble, which celebrates its 25th anniversary this spring. (I wasn’t able to attend all of these sessions, unfortunately.)

Al Wootten (National Radio Astronomy Observatory) gave a nice talk about science that is being done with ALMA so far. It’s an array of 66 12-meter and 7-meter radio telescopes, and after three decades of planning/construction, ALMA is now approaching full science operations. The US is part of a large international collaboration consisting of a partnership between North America, Europe, and East Asia. Wootten presented interesting results about observations of gas in Milky Way-like galaxies in the distant universe and of gas kinematics in protostars and protoplanetary disks. ALMA had a conference in Tokyo in December, and the proceedings will be published in a few months.

The TMT and JWST are upcoming telescopes that much of the astronomical community and the science-loving public are looking forward to. The TMT is one of the giant telescopes I’ve written about before, and it will have “first light” in 2022. JWST is scheduled to launch in 2018.

[This is my second post in a series about the American Astronomical Society meeting.]

Reporting from the American Astronomical Society Meeting: Impostor Syndrome, Publishing Changes, Sustainability

13 January 201521 January 2015 / raminskibba / 4 Comments

[This will be the first of a series of three posts about interesting events at the American Astronomical Society meeting. I plan on writing about some policy issues and scientific results in separate posts.]

When I was taking the train north, I fell asleep in northern California and awoke to sunrise in Oregon. The dry desert-like environment was replaced by the foggy forests and mountains one typically associates with the northwest. You won’t be surprised that it was rainy when we arrived.

In any case, it was great to visit Seattle. Thousands of American and international astronomers, as well as educators and journalists, converged on the convention center downtown two weeks ago for a busy and exciting American Astronomical Society (AAS) meeting, which is annually one of the world’s largest astronomy meetings. I’ll describe a couple of the interesting sessions that involve scientists’ activities and concerns beyond scientific research here and that you might not have heard about elsewhere. (A separate post will address new scientific results and plenary sessions.)

You can view the AAS meeting’s program online, and you can check out everyone’s live-tweeting at #aas225 too.

Impostor Syndrome

Jessica Kirkpatrick, Caitlin Casey, and Kartik Sheth organized an excellent session on the impostor syndrome, and from what I could tell, it was very successful. They packed a large room, and graduate students as well as more senior scientists actively participated in the event. The organizers will soon be posting about it and about survey results on the Women in Astronomy blog, so watch for that.

Many people working in academia have experienced what some psychological researchers refer to as “impostor syndrome.” According to Langford & Clance (1993),

the impostor syndrome is defined by ‘believing that one’s accomplishments came about not through genuine ability, but as a result of having been lucky, having worked harder than others, and having manipulated other people’s impressions.’

As Rachel Ivie and Arnell Ephraim (American Institute of Physics) put it in 2011, “One key aspect of the imposter syndrome is the attribution of your own success to factors beyond your control, such as luck, while attributing the success of others to skill or knowledge.” Based on a survey, they argue that impostor syndrome manifests itself more strongly in women and therefore contributes to a higher
drop-out rate among women than men in astronomy.

Consequently, impostor syndrome is not just harmful to the health and success of the many people who experience it but is also harmful to science in general. Men (including me) experience impostor syndrome too, as do many minority groups such as black and Latino scientists. According to a survey of astronomers planning to the attend the AAS session, 56% of them are experiencing or have experienced severe impostor syndrome. This is clearly an issue we must try to address, and this involves identifying, assessing, and reversing the effects of impostor syndrome.

The session mostly consisted of the participants interacting with each other and going through a series of steps in which everyone talked about the sources of their impostor syndrome feelings and doubts, how they cope with them, and figuring out what to do in order to break the cycle. That last part involves great advice: “Start talking about it. Accept that this is normal. Rewrite your script. Think positive. Redefine success. Stop unrealistic comparisons. Self care. Find a support network. Fake it.”

In my opinion, all of this is great, and more sessions like this should be organized in future AAS meetings. Encouraging everyone and dealing with sources of doubt will help all scientists and students to gain confidence, and this is an important step toward achieving equality in STEM fields. In addition, people at universities and other educational institutions should make an earnest effort especially at the level of graduate programs to discuss and address these issues. Unfortunately, straight white privileged men seem to be the most unaware of these issues are also the people most often in leadership positions and most unlikely to have attended this session. Talking about these issues openly and consistently should help to make everyone more aware of them.

AAS Publishing

In a town hall-style session, people from the AAS publishing program described potential changes to the main journals, including the Astronomical Journal (AJ) and Astrophysical Journal (ApJ) (where I have published papers before). I expect that many of these changes will be officially announced in more detail later this year.

The details will mostly just interest professional scientists who frequently read and publish in these journals. There are plans to balance content in ApJ and AJ and to have one centralized portal for submitting papers. They will eventually do away with ApJ Supplements, as the distinction between them and regular ApJ papers is not as clear as before, and in any case, in an age where most papers are accessed online, the distinction is basically irrelevant. They are planning on technological enhancements in the journals in the future, such as including 3-dimensional figures, video abstracts, and staff support with graphics. Finally, rather than just having ApJ Letters, they proposed the creation of AAS letters, which would highlight the most important research of both the AJ and ApJ and which would not have as strict a length limit.

During the Q&A period, there were comments about open access and about the contrast between the AAS business model and that of the Royal Astronomical Society, which publishes the Monthly Notices of the RAS. In my personal opinion, I think open access journals are generally a good thing, and I prefer the MNRAS model, in which scientists do not have to pay to publish papers; in effect, the cost is paid by libraries and other institutions. In other publishing-related news, a new open-access scientific journal, Collabra, was just introduced in the UK, in which they plan to pay peer reviewers and editors.

Sustainability Efforts

As I wrote in my previous post, where I described my train trip to the AAS, I recently joined the AAS Sustainability Committee. The committee organized a splinter session called “Teach Climate Change!” that was led by James Lowenthal (Smith College), Katy Garmany (NOAO), and others. The session mainly consisted of: (1) discussions about how to teach climate change in an introductory astronomy course; (2) how astronomers can engage in public debate on climate change issues; and (3) how we can address sustainability through control of “light pollution,” though we ended up having not much time for that topic.

We had many lively discussions about these topics and audience members had many excellent ideas. Many people advocated for astronomers to engage in more public outreach programs, including with museums such as the California Academy of Sciences. When teaching a class, it’s useful to assess students’ views anonymously such as with “clickers,” and students can calculate their own carbon footprint on the Environmental Protection Agency’s (EPA’s) website, which would help make these issues more concrete. For interested readers, Lowenthal recommended the 2010 book, Merchants of Doubt, by Naomi Oreskes and Erik Conway, which compares climate change misinformation to that of the tobacco industry.

We will make more information and resources available in the future, and in the meantime, I suggest checking out the Sustainability Committee’s website and blog.

Other Sessions

I’ll just briefly mention a few more sessions at the AAS meeting. On the pre-meeting days, there sessions on astrostatistics and databases with R and Python codes, and one on “distributed collaboration” with Github. There also was a two-day teaching workshop organized by the Center for Astronomy Education; I attended it in 2012 and strongly recommended it. There were other teaching and outreach-related sessions too, including one about the Astronomy Ambassadors, but I only could attend a few of them this time. There were also a few events related to the International Year of Light. Finally, the Historical Astronomy Division (HAD) organized many interesting sessions I was sad to miss—you can’t go to everything when there are many parallel sessions—with titles such as “Astronomy and the First World War” and “Preserving the Material Legacy of the American Observatory Movement.”

Science Writing Awards

Finally, at a reception on 6th January, Rick Feinberg, the AAS Press Officer, announced the science writing awards. Alexandre Witze won the 2014 American Institute of Physics (AIP) Science Communications Award for her excellent article, “Spinning the Core” in Science News, on magnetic dynamos. Lee Billings won the award in the book category for his “Five Billion Years of Solitude”, published by Current/Penguin. I look forward to reading it!

You could say that I attended the AAS meeting as an astronomy researcher, astronomy policy analyst, and beginning science writer. Here’s my badge—for the first time, I was registered as both press and as an astronomer. It’s interesting seeing things from the other side.

All Aboard to the American Astronomical Society Meeting!

2 January 201513 January 2015 / raminskibba / 1 Comment

I’m on a train adventure, going through California, Oregon, and Washington to the American Astronomical Society (AAS) meeting in Seattle. This post is a modified version of one I wrote for the AAS
Sustainability Committee.

For those of you astronomers and journalists at the meeting, you’re welcome to join us for our Special Session next Wednesday (7th January) at 12:30-14:00 in Room 4C-3. We’ll be starting the new year with ideas and plans for addressing climate change issues in class and with the media.

We encourage anyone who is interested in the Sustainability Committee to contact us and get involved. We will post resources on this website for teaching and discussing climate change with journalists.

It’s important for astronomers to try to make observatories, telescopes, university department buildings, and computer centers as energy efficient as possible, but our largest environmental impact and carbon footprint comes from airplane flights to meetings, conferences, workshops, etc. According to a New York Times article, air travel emissions account for about five percent of global warming, and that fraction is projected to rise significantly as the volume of air travel is increasing much faster than gains in flight fuel efficiency.

It would help this situation to develop better resources and technologies for videoconferencing and remote observing, and these are areas where we should continue to make improvements. In addition, long-distance travel can be difficult for some people, such as for those with families and those in relatively remote locations, and videoconferencing and webcasts can make conferences more accessible to more people.

Nonetheless, long-distance travel is sometimes necessary, including for early-career scientists who need to advertise their work and network at conferences. I joined the Sustainability Committee in 2014, and one thing I am trying to do and trying to encourage others to do is to take more trains. In the US, long-distance trains can be very useful depending on where one wants to travel. They are not always the fastest mode of transportation, but they are comfortable, convenient, have great views, and usually have wireless access if you need to work. And importantly, they save energy.

I work at the University of California, San Diego, and I’m taking the train up the Pacific coast to Seattle via Los Angeles, Santa Barbara, which we just passed, the Bay Area, Sacramento, and Portland. (It makes me think of Woody Guthrie’s “This Land Is Your Land.”) I’m traveling nearly 1500 miles (2400 km)—nearly the entire distance from the southern to northern border of the US. As I wrote in a blog post last summer, Amtrak trains expend about 1,600 BTUs of energy per passenger per mile, while planes use 2,500 and cars use 3,900. Trains are much more energy efficient than planes, cars, and buses, and by not flying to Seattle, I’m saving tons of carbon dioxide emissions. This is just a start, but I am trying to view flying as a luxury or necessary evil that I will avoid and reduce when possible.

In any case, I’m excited to be part of the new and improved Sustainability Committee, and if you’re interested, join us at the AAS meeting! More importantly, make a resolution in 2015 to reduce your and your institution’s carbon footprint.

Thoughts on “Interstellar” and Questions it Raises

16 December 20145 May 2016 / raminskibba / 3 Comments

I finally went and saw Christopher Nolan’s Interstellar a couple days ago. It’s definitely an entertaining and thought-provoking movie, and it’s worth seeing in a theater. This post won’t really be a review of the film, but I’ll give you a few of my thoughts about it and implications of it for our role in the universe. I’m interested in hearing your response to the movie as well. It raised some big and important questions that we humans should explore further. (Note: this post includes a few “spoilers,” so consider yourself warned.)

First of all, if you haven’t seen 2001 or Contact already, then you should rectify that immediately! They’re both excellent, and Interstellar was made with many connections and homages to them…so turn off your computer or tablet or brain implant or whatever you’re reading this with, and go check out those movies! You can come back to this blog later.

Also, if you’re interested in checking out other astronomers’ responses to the movie, you can read the excessively critical review and mea culpa by Phil Plait, the interesting tweets and more tweets by Neil deGrasse Tyson, and this article in Wired magazine by Adam Rogers (and thanks to Lynne Friedmann for giving it to me).

Why are astrophysicists discussing or questioning some aspects of the film? It’s because the filmmakers consulted Kip Thorne and did attempt to get the physics right, and because it’s the big space movie of the year, like Gravity was last year. In my opinion, they did do a pretty good job on many issues, though I wasn’t so sure about a couple others: for example, I’m not sure whether all the time dilation effects were calculated accurately (though their take on the “twin paradox” was interesting), and I’m skeptical about Matt McConaughey’s character’s experience in the black hole (which is the circular saw-shaped image above). And deGrasse Tyson made an accurate and important observation that bothered me too: “Mysteries of #Interstellar: Stars vastly outnumber Black Holes. Why is the best Earthlike planet one that orbits a Black Hole”?

I’m not going to get into these physics issues much here. (I’m happy to try to answer any questions you might have though—just post a comment or contact me on Twitter.) Instead, I’m more interested in exploring questions the movie raised. For example, how much of a priority is space exploration to us as a society? How difficult would it be to find another potentially habitable planet—and what are our criteria for “potentially habitable”? How would we traverse these great distances? How do we transport people (and necessary equipment and supplies) so that they can survive for long periods far from Earth—in spacecraft, space stations, or colonies? How vulnerable is our own planet and which vulnerabilities should we be trying to address? How might we eventually contact or even meet alien species, and what would we tell or ask them? Who would do the talking or asking? Will we behave with empathy or will we act like conquerors? What are own roles and responsibilities as Earthlings and citizens of the cosmos?

(We also learned a few fun things from the movie, such as: wormholes can be convenient; books get pushed off of shelves by space ghosts; NASA will survive even during the worst of times; and watch out if you land on an ice planet and find Matt Damon.)

It’s easy to become focused and fixated on short-term and local problems, as they can seem the most pressing. That’s totally understandable, but we as a society can’t forget the big long-term picture. What are our objectives and priorities as a global community? What do we want to achieve, and how can we work toward those goals and help future generations to realize them?

In the movie, a runaway Dust Bowl—presumably due to climate change—or some kind of “nuclear winter” devastates the world’s food supplies. Though this might seem far-fetched, it’s not out of the question for our planet. People had to struggle just to get through each day and to feed their families, such that exploration was the furthest from their minds and people started believe that the Apollo program was a hoax. But the drive to explore the unknown and see what’s out there is an inherently human trait. Carl Sagan once wrote, “Exploration is in our nature. We began as wanderers, and we are wanderers still. We have lingered long enough on the shores of the cosmic ocean. We are ready at last to set sail for the stars.” What are other planets, solar systems, or even other galaxies like, and what do their differences tell us about our own? Just today a Scientific American article came out, where the author discusses the thousands of exoplanets observed so far and argues that “Planets More Habitable than Earth may be Common in Our Galaxy.” These are issues we can’t stop thinking about.

One problem is that space is big. “Really big. You just won’t believe how vastly, hugely, mindbogglingly big it is” (to quote the Hitchhiker’s Guide to the Galaxy). Planets that support life are extremely rare, though we don’t know exactly how rare yet. It’s difficult to learn about planets far away, and it won’t be easy to find out which ones humans could visit or which ones might support alien life. Contacting those aliens is more complicated. And then visiting other planets and solar systems, or even setting up colonies on them is literally a multi-generational project. For example, Alpha Centauri is about 4.4 light years away. If astronauts could travel as fast as the Voyager spacecraft…it would take them 77,000 years to get there! They’d wake up from hibernation in their spaceship after all that time, and they wouldn’t even know whether other humans were still alive.

Finally, one of the main points I think we should take away from the movie is that we must take care of our own planet. Earth is rare, and it’s our home. We face many dangers and threats throughout the world, including global warming, drought, floods, famine, air pollution, natural disasters, pandemics, ozone depletion, killer asteroids, and war. We should note that these problems and their effects are related to poverty and inequality too, and that’s not to mention threats to other species on Earth. We might not survive for thousands of years—which is like a blink of an eye for our universe—but we have to try. We have to work together and plan for the future.

On that note, I’ll leave you with the ending of Carl Sagan’s Cosmos:

We are the local embodiment of a Cosmos grown to self-awareness. We have begun to contemplate our origins: starstuff pondering the stars; organized assemblages of ten billion billion billion atoms considering the evolution of atoms; tracing the long journey by which, here at least, consciousness arose. Our loyalties are to the species and the planet. We speak for Earth. Our obligation to survive is owed not just to ourselves but also to that Cosmos, ancient and vast, from which we spring.

Conference on Nearby Galaxies in Memory of Charles Engelbracht

6 December 201413 January 2015 / raminskibba / 3 Comments

I just returned from a small conference on “Observations of Dust in Nearby Galaxies” at the University of Arizona in Tucson. It honored Chad Engelbracht, an influential astronomer in the field who rather suddenly passed away in January, before his 44th birthday.

It was great to be back in Tucson! This was my first visit since I moved away in 2012. I worked as a postdoc at the University of Arizona—an internationally renowned center of theoretical, observational, and instrumental astronomy—for three years, and I spent much of that time working with Chad on research projects with the Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel (KINGFISH) and Herschel Inventory of The Agents of Galaxy Evolution (HERITAGE) surveys. Chad has written numerous publications on extragalactic infrared astronomy, especially on the distributions of dust, stars, and gas within galaxies in the “local universe.” He was also the MIPS Instrument Scientist for the Spitzer telescope, which enabled a lot of excellent research by others.

As you may know, I’m trained in theoretical astrophysics, and my expertise is in the large-scale structure of the universe, dark matter, galaxy formation, and cosmology, and when I’ve used data, they’ve usually been in optical wavelengths. Needless to say, I had a steep learning curve to navigate in order to work on my infrared research, and Chad helped me up it. Chad was my friend and colleague, and I really enjoyed working with him. He was patient with me, had a great sense of humor, gave me insightful suggestions and feedback, and helped me produce interesting results. (The two main papers we wrote together are here and here.) If I continue with my academic career, he would be one of my role models.

Chad also liked beer, so we definitely got along well. While I worked at Steward Observatory, he and I and others in the “infrared wing” frequently went to 1702 for pizza and beer for lunch. The night before the conference, many of his old friends and I went back to 1702 for a few pints. Chad also liked to play the computer game Quake, where he was known as “Chuckles the clown.” During her opening remarks at the conference, Joannah Hinz said, “Since no one is admitting to have played Quake, it seems that Chad must have been playing it by himself!” Well, I’ll admit that Chad didn’t have to twist my arm much to convince me to play it when I was at Arizona, and when I’d gotten a new computer, his first task was to make sure that Quake ran on it well. The game made for a good afternoon break and a funny way to interact with people. (If you’re wondering, I played as The Tick.)

Many of Chad’s colleagues and collaborators attended and spoke at the conference, including Rob Kennicutt, Margaret Meixner, Bruce Draine, Maud Galametz, and Dennis Zaritsky. I was moved by all of the personal and astronomical tributes to Chad throughout the conference. It’s clear that he influenced, inspired, and was respected by many people. His legacy lives on.

Chad is survived by his parents and siblings, his wife Sue Dubuque, their three children (Max, Sydney, and Henry), and his numerous friends. He is missed.

Rosetta and the Time-scale of Science

26 November 201413 January 2015 / raminskibba / Leave a comment

Over the past couple weeks, you have surely seen Rosetta and its dusty comet all over the internet, in the news, or on Twitter and other social media sites. It has definitely captured the public imagination. But where did Rosetta come from? How did scientists at the European Space Agency (ESA) manage to accomplish the feat of putting a lander on the surface of a comet hurtling through space? The answer: through a lot of hard work by many people and investment of many resources for many years.

#CometLanding may have been the meme of the week, but it was decades in the making. After Halley’s Comet (1P/Halley) flew by the Earth and was studied by ESA’s Giotto probe, scientists there and at NASA realized that more ambitious missions would be necessary to obtain more detailed information about comets, which contain water and organic materials and could have influenced the origin of life on Earth. ESA’s Science Programme Committee approved the Rosetta mission in November 1993, about 21 years ago. Design and construction took teams of scientists a decade to complete, and then they launched the €1.3 billion flagship spacecraft in 2005 (which was a few months before NASA’s Deep Impact mission sent a probe to collide with a different comet). Following four gravity assists, slingshotting once by Mars and three times by Earth, Rosetta rendezvoused with the comet 67P/Churyumov-Gerasimenko earlier this year. After orbiting for two months, Rosetta was in a position and trajectory to eject Philae, which successfully landed on the comet and made history on 12th November. (See my recent post for more.)

To give another example, for my astrophysics research, I have frequently used data from the Sloan Digital Sky Survey (SDSS), an optical telescope at Apache Point Observatory in New Mexico. The SDSS was first planned in the 1980s, and data collection finally began in 2000. Some have
described the SDSS as one of the most ambitious and influential surveys in the history of astronomy, as it has observed millions of galaxies and quasars, transforming many fields of research, including work on cosmology and the large-scale structure of the universe. It also witnessed the rise of Galaxy Zoo, which with more than 250,000 active “citizen scientists,” has become perhaps the greatest mass participation project ever conceived. Now we prepare for the successors to the SDSS, including ESA’s Euclid mission and the Large Synoptic Survey Telescope, funded by the National Science Foundation (NSF), which are expected to have “first light” in the 2020s.

Scientific research operates on a long time-scale, sometimes longer than the careers of scientists themselves. Scientists make mistakes sometimes, and some projects, large and small, may fail or produce inaccurate results. At times, it may take awhile for scientists to abandon a theory or interpretation insufficiently supported by evidence, and it can be difficult to determine which investigations to pursue that could yield new and fruitful research. Nevertheless, over many years the “self-correcting” nature of the scientific enterprise tends to prevail.

In addition, while the US Congress makes decisions about federal budgets every fiscal year, American scientists depend on predictable stable funding over longer periods in order to successfully complete their research programs. Moreover, school and university students depend on funding and resources for their education. Quality scientific education helps people to become scientifically literate and critical thinkers; as Neil deGrasse Tyson put it, “center line of science literacy…is how you think.” Plus, some students will be inspired by Rosetta and other achievements to pursue careers in science, and we should give them every opportunity to do so.

Events can change rapidly in the 24-hour news cycle, but science and scientists work over years to produce big results like the comet landing. Future missions and ambitious projects for the next few decades are being planned now and need continued support. And to ensure more scientific advancements after that, we need to keep investing in the education of our students—the next generation of scientists.

[Note that this op-ed-like piece is adapted from an assignment I wrote for a science writing class with Lynne Friedmann at UC San Diego.]

Comet Update! Rosetta’s Philae landed, but not as planned

20 November 20146 March 2015 / raminskibba / 2 Comments

Now here’s what you’ve been waiting for! You really need more comet, like Christopher Walken/Bruce Dickinson needs more cowbell, so here you go…

In a blog post few months ago, I told you about the European Space Agency’s (ESA’s) Rosetta mission. Nine years after its launch and after four gravity assists, Rosetta reached the comet 67P/Churyumov-Gerasimenko and began to orbit it. On 11th November, Rosetta maneuvered its position and trajectory to eject its washing machine-sized lander, Philae, which sallied forth and landed on the comet the next day, and MADE HISTORY! (Wired‘s apt headline, “Holy Shit We Landed a Spacecraft on a Comet,” beat The Onion, which is known for that sort of thing.) Its landing was confirmed at ESA’s Space Operations Centre in Darmstadt, Germany at 17:03 CET that day.

Above you can see Philae on its fateful journey, and below you can see its first image of the comet, both courtesy of ESA. The landing happened to take place while friends of mine were at a Division of Planetary Sciences meeting in Tucson, Arizona, and we and others discussed the Philae landing at Friday’s Weekly Space Hangout with Universe Today. And if you’re interested in more information than what I’ve written here, then check out the ESA Rosetta blog and posts by Emily Lakdawalla, Matthew Francis, and Phil Plait.

From what we can tell, Philae did initially touch down in its predicted landing ellipse (its planned landing zone) but its harpoons—which were supposed to latch onto the surface—failed to fire, and it bounced! Considering how small the comet is and how weak its gravitational force (about 100,000 weaker than on the Earth), this could have been the end as the lander could then have floated away, never to be seen again. However, after nearly two hours, it landed again…and bounced again, and a few minutes later finally settled on the surface and dug in its ice screws, about 1 km from its intended landing spot on a comet 4 km in diameter. (This would be like trying to land a plane in Honolulu and ending up on another island—it’s unfortunate but at least you didn’t drown.)

At first, it wasn’t clear exactly where Philae actually was; it could have dropped into a crater where it would be nearly impossible to find. But then based on images from the OSIRIS camera and NavCam (navigational camera) on Rosetta, ESA scientists were finally able to locate it a couple days ago. The mosaicked images above came from the OSIRIS Team, and the NavCam image below as annotated by Emily Lakdawalla, to give the larger-scale context. After its last bounce, Philae rotated and headed “east”, finally becoming settled among dust-covered ice at the bottom of a shadowed cliff. It’s not an ideal position but at least it’s not totally precarious. (They considered securing the position with the harpoons, but the momentum from firing them could push the lander back up into space, which would be “highly embarrassing” according to Stephan Ulamec, head of the lander team.)

But the cliff situation is a problem. Philae’s battery had a little more than two days of juice in it, and once that ran out, it would be dependent on its solar panels. However, Philae’s current position only receives about 1.5 hours of light per 12-hour rotation of the comet, much less than hoped. Philae did attempt to run some of its experiments and activities during the time allotted, the battery ran late on Friday. This was @Philae2014’s last tweet: “My #lifeonacomet has just begun @ESA_Rosetta. I’ll tell you more about my new home, comet #67P soon… zzzzz #CometLanding”

Before Philae dreamt of electric sheep, it managed to collect some data using instruments on board. (See this Nature news article.) For example, Philae deployed its drilling system (SD2) as planned, in order to deliver samples to the COSAC and Ptolemy instruments, which probe organic molecules and water (and which I described in my previous Rosetta post). But ESA scientists don’t know how much material SD2 actually delivered to the lander; if the ground is very dense, it’s possible that since Philae isn’t totally anchored, it could have moved the lander rather than drilling into the surface. We do know for sure that some instruments operated successfully, such as the downward-looking ROLIS camera and ROMAP, the magnetic field mapping system.

In any case, scientists have obtained some data already while other data stuck on the snoozing lander will be retrieved later. In the meantime, Rosetta is keeping busy and continues to take observations. Philae has already been a success, and who knowsmaybe it will “wake up” when its solar panels absorb enough sunlight to recharge the batteries.

[Note that the NavCam images we’ve seen so far are pretty good, but I have heard that Rosetta scientists have much better resolution color images that are embargoed and won’t be released for six months. I haven’t confirmed this fact yet, so if you have more up-to-date info, please let me know.]

Finally, I’ll end with some comments about what some people are referring to as #shirtstorm or #shirtgate. (For more info, see this Guardian article and this blog post and this one.) On the day of the worldwide live-stream broadcast last week, Matt Taylor, the Rosetta Project Scientist, wore a shirt covered with scantily clad women. I get the impression that Taylor is a cool guy and wants to get away from the scientist stereotypes people have, but this is completely inappropriate. (And he’s worn this shirt to work before. Apparently none of his colleagues told him to leave it at home.) But it’s not just the shirt; during the middle of his broadcast, Taylor referred to Rosetta as the “sexiest” mission. “She’s sexy, but I never said she was easy.”

We debated many aspects of this on astronomers’ official and unofficial social media, and for the most part, our community is very unhappy about this. You may say that we should focus on the science, and who cares about what this scientist wears or says when he’s excited about his mission’s success. But we have been working really hard to increase diversity in STEM fields and to achieve gender equality in science. Many aspects to working in the current scientific establishment are not particularly welcoming to women, and Matt Taylor’s shirt and poor choice of words are part of the problem. A few days later, Taylor made a heartfelt apology. As far as I know, ESA itself has not issued an official apology yet. The American Astronomical Society made a statement today (Wednesday) that “We wish to express our support for members of the community who rightly brought this issue to the fore, and we condemn the unreasonable attacks they experienced as a result, which caused deep distress in our community. We do appreciate the scientist’s sincere and unqualified apology.”

In any case, our focus is on the science and on this amazing scientific achievement. But Science is for everyone.

Rise of the Giant Telescopes

11 October 201420 January 2015 / raminskibba / 5 Comments

The biggest telescope ever constructed, the Thirty Meter Telescope (TMT), officially broke ground on Mauna Kea in Hawai’i on Tuesday. Building on technology used for the Keck telescopes, the TMT’s primary mirror will be segmented combining 492 hexagonal reflectors that will be honeycombed together, and it will have an effective diameter of 30 meters, as you’ve probably guessed. (Astrophysicists come up with very descriptive names for their telescopes and simulations.) 30 meters is really really big—about a third the length of an American football field and nearly the size of a baseball diamond’s infield. When it’s built it will look something like this:

(If you’re interested, here’s a shameless plug: we discussed the TMT’s groundbreaking on the Weekly Space Hangout with Universe Today yesterday, and you can see the video on YouTube.)

The groundbreaking and blessing ceremony, which included George Takei hosting a live webcast, didn’t go quite as planned. It was disrupted by a peaceful protest of several dozen people who oppose the telescope’s construction. The protesters chanted and debated with attendees and held signs with “Aloha ‘Aina” (which means ‘love of the land’) and using TMT to spell out “Too Many Telescopes.” There has been a history of tension over what native Hawaiians say is sacred ground in need of protection and is also one of the best places on Earth to place telescopes. This is a longstanding issue, and the tension between them back in 2001 was reported in this LA Times article. According to Garth Illingworth, co-chair of the Science Advisory Committee, “It was an uncomfortable situation for those directly involved, but the way in which the interactions with the protesters was handled, with considerable effort to show respect and to deal with the situation with dignity, reflected credit on all concerned.” In any case, construction will continue as planned.

The TMT’s science case includes observing distant galaxies and the large-scale structure of the early universe, and will enable new research on supermassive black holes, and star and planet formation. The TMT is led by researchers at Caltech and University of California (where I work), and Canada, Japan, China, India. Its optical to near-infrared images will be deeper and sharper than anything else available, with spatial resolution twelve times that of the Hubble Space Telescope and eight times the light-gathering area of any other optical telescope. If it’s completed on schedule, it will have “first light” in 2022 and could be the first of the next generation of huge ground-based telescopes. The others are the European Extremely Large Telescope (E-ELT, led by the European Southern Observatory) and the Giant Magellan Telescope (GMT, led by the Carnegie Observatories and other institutions), which will be located in northern Chile.

Every ten years, astronomers and astrophysicists prioritize small-, medium-, and large-scale ground-based and space-based missions, with the aim of advising the federal government’s investment, such as funding through the National Science Foundation (NSF) and NASA. The most recent decadal survey, conducted by the National Academy of Sciences is available online (“New Worlds, New Horizons in Astronomy and Astrophysics“). For the large-scale ground-based telescopes, the NSF will be providing funding for the Large Synoptic Survey Telescope (which I’ve written about here before) and the TMT. There had been debates about funding either the TMT or the GMT, but not both, though a couple years ago GMT scientists opted out of federal funding (see this Science article). NASA is focusing on space-based missions such as the upcoming James Webb Space Telescope (JWST) and Wide-Field InfraRed Survey Telescope (WFIRST), which will be launched later this decade.

Astrophysicists Gather in Aspen to Study the Galaxy-Dark Matter Connection

8 September 20142 February 2015 / raminskibba / Leave a comment

I just returned from a summer workshop at the Aspen Center for Physics, and I enjoyed it quite a bit! The official title of our workshop is “The Galaxy-Halo Connection Across Cosmic Time.” It was organized by Risa Wechsler (Stanford) and Frank van den Bosch (Yale) and others who unfortunately weren’t able to attend (Andreas Berlind, Jeremy Tinker, and Andrew Zentner). The workshop itself was very well attended by researchers and faculty from a geographically diverse range of institutions, but since it was relatively late in the summer, a few people couldn’t come because of teaching duties.

Since I grew up in Colorado, I have to add that Aspen is fine and I understand why it’s popular, but there are many beautiful mountain towns in the Colorado Rockies. Visitors and businesses should spread the love to other places too, like Glenwood Springs, Durango, Leadville, Estes Park, etc… In any case, when we had time off, it was fun to go hiking and biking in the area. For example, I took the following photo after hiking to the top of Electric Peak (elev. 13635 ft., 4155 m), and lower down I’ve included photos of Lost Man Lake (near the continental divide) and the iconic Maroon Bells.

The Aspen Center for Physics (ACP) is a great place for working and collaborating with colleagues. As they say on their website, “Set in a friendly, small town of inspiring landscapes, the Center is conducive to deep thinking with few distractions, rules or demands.” As usual, we had a very flexible schedule that allowed for plenty of conversations and discussions outdoors or in our temporary offices. Weather permitting, we had lunch and some meetings outside, and we had many social events too, including lemonade and cookies on Mondays and weekly barbecues. It’s also family-friendly, and many physicists brought their spouses and kids to Aspen too. I’ve attended one ACP summer workshop on a similar theme (“Modeling Galaxy Clustering”) in June 2007, and it too was both fun and productive. Note that the ACP workshop is very different than the Madrid workshop I attended earlier this summer, which had specific goals we were working toward (and I’ll give an update about it later).

This year’s Aspen workshop connected important research on the large-scale structure of the universe, the physics of dark matter halo assembly, the formation and evolution of galaxies, and cosmology. We had informal discussions about the masses and boundaries of dark matter haloes in simulations, ways to quantify the abundances and statistics of galaxies we observe with telescopes and surveys, and how to construct improved models that accurately associate particular classes of galaxies with particular regions of the “cosmic web”—see this Bolshoi simulation image, for example, and the following slice from a galaxy catalog of the Sloan Digital Sky Survey:

While some of these issues have plagued us for years and remain unresolved, there are some subtle issues that have cropped up more recently. We (including me) have successfully modeled the spatial distribution of galaxies in the “local” universe, but now we are trying to distinguish between seemingly inconsistent but similarly successful models. For example, we know that the distribution of dark matter haloes in numerical simulations depends on the mass of the haloes—bigger and more massive systems tend to form in denser environments—as well as on their assembly history (such as their formation time), but these correlations can be quantified in different ways and it’s not clear whether there is a preferred way to associate galaxies with haloes as a function of these properties. For the galaxies themselves, we want to understand why some of them have particular brightnesses, colors, masses, gas contents, star formation rates, and structures and whether they can be explained with particular kinds of dark matter halo models.

The main purpose of these workshops is to facilitate collaborations and inspire new ideas about (astro)physical issues, and it looks like we accomplished that. The previous workshop I attended helped me to finish a paper on analyzing the observed spatial distribution of red and blue galaxies with dark matter halo models (arXiv:0805.0310), and I’m sure that my current projects are already benefiting from this summer’s workshop. We seem to be gradually learning more about the relations between galaxy formation and dark matter, and my colleagues and I will have new questions to ask the next time we return to the Rockies.

Finally, here are those Maroon Bells you’ve been waiting for: