Author: bwillman

Lots of Haverford astronomy news to report, but I’m just going to focus on the Large Synoptic Survey Telescope (LSST) project and its role at Haverford for this post.  The LSST is a ~ $500 million optical survey telescope that is in its design, development, and construction phase.  It will be an 8m telescope that will have a camera with a 10 square degree field of view.  This telescope will live in Cerro Pachon, Chile and is expected to begin survey operations in 2018.  This survey of the sky will be groundbreaking in many ways; I will only highlight a couple.  With the ~1000 visits (combined over all filters, after 10 years) to all locations in the Southern sky, this survey will be the only one that can generate a deep map of a large fraction of sky in the time domain:  LSST will make a movie of the sky (I think that is a Tony Tyson quote, but I can’t remember).  With so many visits, LSST will also provide the deepest and most sensitive map of half of the celestial hemisphere reasonably possible from the ground at optical wavelengths. And…. (drumroll)… all of the data will be public immediately, enabling professional astronomers, enthusiasts, teachers and students anywhere to participate in ground breaking reasearch.

I’ve just returned from an All Hands Meeting for this project in my capacity as co-chair of the Milky Way and Local Volume Structure science collaboration.  The meeting was at a Ritz-Carlton resort outside of Tucson, AZ.  I now understand why Ritz-Carlton has such a good reputation: the hotel, service, food, and setting were all completely fantastic.  I couldn’t get over it the entire time.  Lucky for me, the science and professional company were also unbeatable.  Its been an amazing experience to participate in the development phase of LSST, an exciting project that I strongly believe in.  One reason that I am so excited about the LSST project is the impact it will have on the science that I work on – near-field cosmology using resolved stellar populations in the local universe.  The stellar density, proper motion, and photometric chemical abundance maps that LSST will enable will be transformative for this field.

A big topic of chatter during this meeting was the impending August 13 release of the results of the Decadal Survey of astronomy.  From the American Astronomical Society’s email to members this week: “It is difficult to overemphasize the importance to our discipline of the decadal survey recommendations. Congress, the White House, and the funding agencies applaud us for undertaking this effort, and they will use our community priorities to allocate federal resources to astronomy and astrophysics projects.”  I returned August 13 to Haverford on a redeye flight so had to miss out watching the live webcast of the survey results with my LSST colleagues … which is too bad because LSST was ranked as the top priority for large, ground-based astronomy projects for the next decade!

This brings me to the role my involvement with LSST has been playing at Haverford.  (This post is long already, so I won’t talk about research outside the classroom).  In all of the classes I teach, I bring my experience doing survey science (both Sloan Digital Sky Survey and LSST).  My first year and sophomore students use Galaxy Zoo, a citizen science project using SDSS data.  I write some LSST inspired calculations for my sophomore level, calc-based class for astro and astrophysics majors.  The biggest impact is in my Galactic Astronomy class for junior and senior majors.  A large portion of the credit for this class is in the form of a research project.  The first time I taught this class, I had all students either use SDSS data to study the Milky Way or develop a science case for LSST along the lines of the Science Book that the collaboration was writing at the time.  They wrote their results in a paper and presented their results in a workshop style format.  I used this opportunity to teach students how to do research while also teaching them about the process of developing a large scientific project.  This Spring, I will have all of my students do their research projects on LSST science.  The current plan is to have them all analyze different aspects of the growing simulated data that are available for LSST.  This will be an awesome way for them to be involved with this developing project, and I think the top ranking bestowed upon LSST will help to inspire the students even more.

I’ll post soon about Haverford’s new telescope resources, so stay tuned for that!

In addition to all of the off campus research that our students have posted about on Astronoblog, four Haverford astronomy students spent 10 weeks of summer research in the Willman lab.  [See cute picture of the team in the Astronomers at Play post.]  We had a great summer together – even more together than I anticipated.  Owing to a thunderstorm induced power failure, my iMac was in the hospital for most of the summer while I worked in my basement lab with the students.

Gail Gutowski (’10) spent the summer wrapping up her photometric analysis of the Willman 1 object, based on data obtained at Kitt Peak National Observatory in 2006.  We are hoping to submit the paper before the end of this year, but it may be delayed a bit because of the many technical problems encountered during artificial star testing.

Oliver Elbert (’11) embarked on an analysis of an N-body + SPH simulation of a Milky Way-massed galaxy formed in a cosmological context.  In particular, he studied the halo of this galaxy and “observed” it the way the LSST project will observe the actual Milky Way based on RR Lyrae stars.  This is a work in progress and will form the basis for Oliver’s thesis.  Maybe he will have a cool animation to post here in the Fall.

Maya Barlev (’12) and Miriam Fuchs (’13) both studied ultra-faint galaxies.  They began by learning the ropes of IDL programming and dwarf galaxy basics through compiling an extended version of Wolf’s/Kalirai’s recent Milky Way dwarf satellite catalogs.  They then studied the detectability of “stealth galaxies” – particularly low surface brightness galaxies – around the Milky Way, inspired by the detection of And XIX around M31 and by Bullock et al’s recent prediction that there may be very stealthy galaxies still hidden around the Milky Way.  Maya wrote a lot of software to simulate, and then to search for, fake stealth galaxies.  Miriam studied the statistics of randomly distributed fields of stars analyzed with different algorithms in an attempt to quantify “significant detection”.  Jen Campbell (’11) will join this project when she returns in the Fall, and bring some of these threads forward to completion for her thesis work.

Me?  I spent a lof ot time collaborating on these projects.  I also gave 3 different talks [at a particle physics workshop, a colloquium, and at a conference] and provided some support for a couple of papers (one computational, one observational) that were accepted/submitted during the summer.  I overcame tough technical setbacks (read: file server disaster) and finally submitted a paper that has been a long time coming – a spectroscopic study of the Willman 1 object.  At the end of the day, we argued that this thing is (or was) a dwarf galaxy based on the fact that two of its member stars have iron abundances that differ by an order of magnitude.  The total luminosity of the Wil 1 object is less than 1000 times that of the Sun (which is less than the luminosity of the individual stars that my Swarthmore colleague, David Cohen, studies!) but we believe that it is a galaxy, or the remnants thereof.  I’m eagerly awaiting the arrival of Ross Fadely, the postdoc who will be joining our group in a couple of weeks and eagerly awaiting moving away from studying my namesake object.

Now, I’m preparing to attend the All-Hands collaboration meeting for the Large Synoptic Survey Telescope (LSST) project next week in my capacity as (co-)chair of the Milky Way and Local Volume Structure science collaboration.  Fingers crossed for the role of LSST in the Decadal Survey report to be released a week from today

(Although posted by bwillman, this post was written by Miriam Fuchs)

My name is Miriam Fuchs, I’m a sophomore at Haverford, and working with Beth Willman this summer doing research on ultra-faint dwarf galaxies. Last Friday, our research team left INSC basement and headed to Jim Thorpe, PA, where we went whitewater rafting down the Lehigh River.

It was a beautiful day for rafting. First things first,: a necessary stop at Dunkin’ Donuts, where we fueled up for the day. After an initial “detour” (we may be good at finding dwarf galaxies, but finding the rafting site…..), we got to Pocono Whitewater, where we were given life vests, paddles, and safety instructions.

And then we were on our way! It was so relaxing just to be in the sun, soak up some rays, and battle some mini rapids along the way. Every so often, we were allowed to jump in the water and float around. One lesson learned that day: don’t mess with science folks when it comes to water splashing. Needless to say, everyone was drenched with water within the first 20 minutes. Midday, we stopped for a lunch of hot dogs, chips and lemonade. After that, the Willman group re-united for the last leg of the trip, and enjoyed a nice series of almost-rough rapids.
Before coming back to Haverford, we stopped off at Annie’s Ice Cream, where we indulged our sweet tooths and got milkshakes and sundaes. Yum yum. All in all, a great day!

Beth Willman, here.  Last Wednesday, I spent the day visiting Swarthmore College’s astronomers: David Cohen and Eric Jensen.  We had a great time talking about our own research, comparing notes on student research and teaching, and discussing the possibility of increasing the cross-pollination between Swarthmore’s and Haverford’s astronomy programs.  (side note: I learned that Professor Cohen also loves squids, although I professed neither my own interest in squids and other sea creatures nor that my cluster of computers has a sea creature naming scheme, with the lead computer being named Squid.)

Swarthmore has a great astronomy program that nicely complements our own.  Whereas Haverford’s expertise is in galaxies and cosmology, Swarthmore’s expertise lies in stars and planets.  This led us to discuss ways to take advantage of these strengths by coordinating when we teach classes on X topic and by encouraging students to take classes at the other campus.  We even very briefly mentioned the possibility that “trading” faculty for a class here or there could be more successful than trading students.  In the Fall, Cohen will be teaching what should be a great Interstellar Medium seminar that meets Wednesday afternoons for 2.5 hours.  (side note number two: the interstellar medium is a lot more exciting and fascinating than its name may initially lead one to believe).  I intend to advertise this to Haverford students.  One tricky bit about encouraging students to take courses at both campuses in astronomy is that it would be particularly difficult for athletes to take an afternoon class at the other campus, because they couldn’t get back by 4 pm for practice.

A final cool thing I learned about is a nifty gadget called a “SunSpotter”(tm).  I’d love to get a handful of these to use in our Astronomical Ideas and Introduction to Astrophysics I classes.

Beth Willman, assistant professor, here.  I just wrapped up at a meeting held in Lyon, France from June 14 – 18 titled “A Universe of Dwarf Galaxies”.  Overall, the conference was very well organized, with plenty of time set aside for poster viewing and discussion.  The lunches were also ridiculously good (3 course, sit down lunches plus wine). There were over 150 participants at this meeting, so there were loads of excellent talks and posters.

This meeting included a broad range of presentations about many aspects of dwarf galaxy formation and evolution (as well as some star clusters thrown in for good measure).   There was even some discussion about “What is a galaxy?”, but it was contained to the session about Ultra Compact Dwarf galaxies (UCDs).  Even though these objects are called “dwarfs”, there isn’t uniform agreement about whether they are the high-mass end of globular star clusters or whether they are instead galaxies.  I think they are star clusters, but agree that it may not be 110% clear.

The observational result presented at this conference that stood out as the most new and exciting was a new result found by Sergey Koposov and collaborators, as presented by Matt Walker (one of Sergey’s collaborators).  Their team has been awarded a large amount of time on the VLT to obtain many repeat measurements of individual stars belonging to the very least luminous galaxies known in the universe.  This is important to investigate the effects of binary stars which could potentially have a huge effect on the observed dynamics of these tiny galaxies. Matt Walker showed the results of 21(!) epochs of imaging of stars in the Bootes I galaxies, and the velocity dispersion of 3 km/sec they computed from their dataset.  The dataset was to die for.  I look forward to seeing their upcoming paper, to read about the technique in more detail and to seeing the results they obtain from their other targets.

My own talk was about observational biases in our current census of the least luminous galaxies known in the universe and on imminent/future prospects for overcoming those biases. (I’m the world expert in the detectability of the teeniest galaxies in the universe, if I may say so myself.)

The ample time for discussion was my favorite part of the workshop, because it gave me a chance to speak with many of my current colleagues that I don’t typically get to see in person, including (in no particular order): Ricardo Munoz, Dave Sand, Evan Kirby, Erik Tollerud, Helmut Jerjen, and Gary Da Costa.  I have lots of ongoing projects to talk with all of those folks about; unfortunately time ran short for science chats because I arrived a bit late and I didn’t have much of a chance to talk with some other folks that I wanted to – like Nicolas Martin from MPIA.

I also got to spend quality time with some friends and older colleagues of mine, including (in no particular order): Julianne Dalcanton, Lucio Mayer, and Gurtina Besla.  Gurtina is a computational astrophysics graduate student at Harvard I got to know when I was there as a postdoc. It was great to have the chance to catch up with her.  We had dinner one night with Julianne Dalcanton, my dissertation advisor and then also on the last night of the conference. She is an expert in modelling the Magellanic Clouds.   Au revoir for now!

The end of the academic year might seem like a strange time to begin a blog, but there is usually something interesting happening in Haverford’s astronomy program.  So no time like the present!

One of the best things about astronomy at Haverford is our great students.  During final exam week, I hosted a dinner party at my apartment for my astronomy research students and students in my classes.  Armed with some photos from this festive event, I’m going to open up Astronoblog by celebrating the six seniors that just graduated with a degree in either Astronomy or Astrophysics.

Here I am with my three freshly graduated seniors: Alex Warres, Dylan Hatt, (me), and Gail Gutowski.  I’m pretty sure Alex is going to be a teacher at an astronomy camp this summer.  Dylan is soon heading to Max Planck Institute in Germany with a Fulbright fellowship to study astronomy.  Gail is now at Haverford to write a paper on her thesis work and will then head to UT Austin for a geophysics research position.

Here is Scott Ogden (left) with his advisor Steve Boughn.  Steve is another astronomy professor here.  Unfortunately for us, Steve will be on sabbatical for the next year.  Scott is heading off to earn a master’s degree in applied math at Stonybrook.

Last, but certaintly not least, are Tyler Evans and Nick Vechik.  Missing between them is Bruce Partridge, their research advisor and my esteemed predecessor.  Bruce had just flown in from a meeting in Paris so needed to retire from the party early.  Nick worked with Bruce on both radio astronomy research and on astronomy education.  He might continue some of his work over the summer.  Tyler may also continue working with Bruce over the summer, and will then head to Swinburne University in Australia for a PhD program in astronomy.

After all of these student-advisor photo ops, the students suggested a group shot with Scott Shelley, the physics lab instructor who taught all of them in multiple lab classes:

Congratulations to all six of our seniors for their past accomplishments and bright future prospects!