2018-02-05: Seminar: Melissa Graham

When: February 5, 2018 @ 12:30-1:30pm 
Where: PAB, WRF Data Science Studio, 6th floor

Mini-Workshop: Alert Stream Filters for Your ZTF Science Goals

The seminar will start with a brief presentation of some of the main ZTF science drivers that require Alert Stream filters, and then we will add our own ZTF science goals and, as a group, create a Filter Wish List. Another brief presentation of the current Alert Packet contents will be provided, with a focus on the schema keys that are most likely to be used in a filter. We will then break into small groups and attempt to write conceptual-level algorithms for the filters on our wish list, and collect these into a single document. We will finish with a group discussion of the main problems/questions faced in our filter-writing attempts. The compiled Filter Wish List document and common issues faced will be used in the near future by the local UW ZTF alert stream team. If you’re not yet sure what kind of time-domain science you might do with ZTF, please do join us — hopefully one of the topics will be inspiring! Should you want to review the basics of the ZTF survey prior to this workshop, see Bellm et al. (2014): http://adsabs.harvard.edu/abs/2014htu..conf…27B

Visitors: Andreas A. Berlind

February 1-2, 2018.

Seminar on February 2, 2018 @ 1:00pm

I am currently an associate professor in the Astronomy Group in the Physics and Astronomy Department at Vanderbilt University. My research interests lie in the areas of large-scale structure and galaxy formation, as well as ultra-high energy cosmic rays. I completed my Ph.D. degree in Astronomy at the Ohio State University, and my A.B. degree inAstrophysical Sciences at Princeton University. Before that, I lived in Athens, Greece where I attended Athens College.

2018-02-02 Seminar: Andreas A. Berlind, Vanderbilt University

When: February 2, 2018 @ 1:00-2:00pm 
Where: PAB, 3rd floor, B305

From Dark Matter to Galaxies: Probing the Spatial Structure of the Universe on Small Scales

The last decade has seen an explosion of high precision measurements of the structure of the universe, courtesy of large galaxy surveys such as the Sloan Digital Sky Survey (SDSS). Galaxy clustering measurements encode information about the nature and abundance of dark matter and dark energy, as well as the complex physical process of galaxy formation. However, harnessing the full constraining power of the data is very challenging since it requires a detailed understanding of the statistical and systematic uncertainties in both data and models, which in turn demands significant computational effort. I will discuss my ongoing research program to analyze SDSS data and model it with the help of cosmological N-body simulations, highlighting results from both recent and ongoing projects.

 

 

Visitors: Adrian Price-Whelan

January 23-24, 2018.

Adrian Price-Whelan is a Lyman Spitzer, Jr. Postdoctoral Fellow in the Department of Astrophysical Sciences at Princeton University. 

You can hear his talk at the Brown Bag Seminar on January 24th, at noon, in the B305 (PAB).

 

DIRAC Researcher Helps Investigate the “Most Mysterious Star” from the Kepler Mission

DIRAC Researcher and NSF Postdoctoral Fellow, James Davenport, is a coauthor on a recent paper studying “Boyajian’s Star”, aka the Most Mysterious Star in the Universe! KIC 8462852, as the star is officially known, has been observed to undergo dramatic changes in brightness over several days, as well as smaller long-term variations. Both of these forms of variability have been unexplained so far, but this latest paper (including Davenport and UW grad student , Brett Morris) finds that clumpy dust surrounding KIC 8462852 is the most likely explanation.

For more information, see this UW Press Release

2018-01-24 Brown Bag: Adrian Price-Whelan, Princeton University

When: January 24, 2018 @12:00-1:00pm 

Where: B305 (PAB) 

Very wide binaries and comoving stars in the Gaia era

Conatal and coeval stars are important tracers of kinematics, stellar models,
dark matter physics, and star and planet formation processes in the Galaxy:
The disruption of these systems is sensitive to the Galactic gravitational
field, their spectra can be used to calibrate stellar models at fixed age and
chemical abundances, and changes or differences in their surface abundances
likely relates to the stability and mass in planetary systems.
A strong indicator that a given pair of stars are coeval is that they are
comoving in three dimensions.
I’ll discuss our group’s effort to identify large samples of comoving stars
(widely-separated or recently dissociated stellar multiplets) using astrometric
data from the Gaia mission, combined with spectroscopic followup.
With astrometry from the (mostly local) Gaia data release 1, we have already
found some surprises: confidently coeval stars separated by >1 pc, and a wide
binary with abundance differences that match rocky abundance patterns.
In anticipation of at least an order of magnitude increase in the number of
comoving stars in Gaia data release 2, I’ll also discuss prospects for (1) using
their kinematics to study the gravitational field of the Milky Way, and (2)
using their chemical abundances to study star formation and the outcomes of
planet formation.

Adrian’s website

 

DIRAC Postdoctoral Positions

The DIRAC Institute in the Department of Astronomy at the University of Washington is seeking applicants with a strong research record in the development of statistical techniques or algorithms for analyzing large astrophysical data sets for two postdoctoral positions.

AstroML: The first position is to help in the development of the second edition of astroML (http://astroml.org) a popular Python-based machine learning package for astrophysics. New components we are incorporating within astroML include methodologies from deep learning and hierarchical bayesian statistics. Special emphasis will be placed on building a broader community and making astroML a sustainable open-source project. The successful candidate will lead these activities, including the application of the new codes to dataset available to UW researchers.

Time Series Data: The second position is to develop new approaches for analyzing astronomical time series data using modern computational frameworks. The goal of this framework will be to enable science with the ZTF and LSST data sets. Promising applicants should possess an interest in time domain science and experience or interest in the use of databases and large scale compute platforms such as Spark, Dask, or similar. Good Python skills, and experience with machine learning libraries, image processing of astronomical images, or astronomical databases are desirable.

The DIRAC Institute is a newly formed center for data intensive astrophysics at the University of Washington. The Institute consists of six faculty and senior fellows, and over 20 postdoctoral researchers and research scientists. It has active research programs in Cosmology, Solar System science, Milky-Way structure, the Variable and Transient universe, andAstronomical Software.

The University of Washington is a partner in the Zwicky Transient Facility (ZTF) project, a new time-domain survey which will begin operations in early 2018. The UW is a founding partner of the LSST project, and leads the construction of its time domain and solar system processing pipelines. Other research activities at UW/DIRAC include topics in extragalactic science, as well as the understanding the structure, formation, and evolution of the Milky Way using large surveys (SDSS, WISE, PanSTARRS PS1, and others).

A Ph.D. degree in astronomy, physics, computer science, or a related subject is required. The initial appointment is for two years, renewable up to three years, and offers competitive salary and benefits. The appointments are available immediately and are expected to start no later than September 2018.

Applicants should submit a curriculum vitae, description of research interests (with links to Github if relevant) and arrange for three letters of reference to be submitted to Nikolina Horvat at horvat@uw.edu with subject line “DIRAC postdoc application (your name)”. Applications will be accepted until the positions are filled, to assure full consideration, please send your application by Dec 31st 2017

For detailed information about the benefits available through the University of Washington, including dental, medical and disability insurance, retirement, and childcare centers, see the University of Washington benefits page: https://www.washington.edu/admin/hr/benefits/.

The DIRAC Institute is a community of people with diverse interests and areas of expertise, engaged in the understanding of our universe through the analysis of large and complex data sets. We are an open, ethical, highly engaged and collaborative community based on trust, transparency and mutual respect. We believe in providing a welcoming and inclusive environment, in the importance of quality of life, in embracing diversity, in making a difference and having fun.

DIRAC Fellowship Positions

We invite applications for up to three DIRAC Postdoctoral Fellows in the Department of Astronomy at the University of Washington. These 3-year DIRAC Fellowships are available to promising, early career researchers interested in the application of novel statistical and computational techniques to fundamental questions in astrophysics. Applicants should demonstrate excellence in research that either complements or builds upon ongoing research directions within the DIRAC Institute. Successful candidates will work with the current DIRAC faculty and researchers to develop their own programs of research and innovation.

The DIRAC Institute  (https://dirac.astro.washington.edu) is a newly formed center for data intensive astrophysics at the University of Washington. The Institute consists of six faculty and senior fellows, and over 20 postdoctoral researchers and research scientists. It has active research programs in Cosmology, Solar System science, Milky-Way structure, the Variable and Transient universe, and Astronomical Software.

The University of Washington is a partner in the Zwicky Transient Facility (ZTF) project, a new time-domain survey which will begin operations in early 2018. The UW is a founding partner of the LSST project, and leads the construction of its time domain and solar system processing pipelines. Other research activities at UW/DIRAC include topics in extragalactic science, as well as the understanding the structure, formation, and evolution of the Milky Way using large surveys (SDSS, WISE, PanSTARRS PS1, and others).

A Ph.D. degree in astronomy, physics, computer science, or a related subject is required. The initial appointment is for two years, renewable for a third year, and offers competitive salary and benefits. The appointment is expected to start no later than September 2018.

Applicants should submit a curriculum vitae, description of research interests (with links to Github if relevant) and arrange for three letters of reference to be submitted to Nikolina Horvat at horvat@uw.edu with subject line “DIRAC Fellowship application (your name)”. Applications will be accepted until the positions are filled, to assure full consideration, please send your application by Dec 31st 2017

For detailed information about the benefits available through the University of Washington, including dental, medical and disability insurance, retirement, and childcare centers, see the University of Washington benefits page: https://www.washington.edu/admin/hr/benefits/.

The DIRAC Institute is a community of people with diverse interests and areas of expertise, engaged in the understanding of our universe through the analysis of large and complex data sets.  We are an open, ethical, highly engaged and collaborative community based on trust, transparency and mutual respect. We believe in providing a welcoming and inclusive environment, in the importance of quality of life, in embracing diversity, in making a difference and having fun.

2017-12-13 Brown Bag: R. Michael Rich, UCLA

When: December 13, 2017 @12:00-1:00pm 
Where: B305 (PAB)
 

The Halos and Environments of Nearby Galaxies (HERON) survey

We have used a dedicated 0.7m telescope to image 123 galaxies in the Local Volume
to ~ 30 mag/sq arcsec. We find a broad correlation between luminosity and halo diameter.
Spiral and lenticular galaxies have similar halo diameters, while the largest halos
(~100 kpc diameter) are found in elliptical galaxies.  Extreme interactions are found
throughout the color-magnitude diagram, but most prominently in the blue cloud. It is also
likely that no meaningful constraints on halo mass for face-on disk galaxies can be gleaned
low surface brightness imaging. Related interesting problems, such as tidally disrupting
dwarfs, low level star formation near elliptical galaxies, and interactions in Hickson compact
groups, will be presented.

 
 

Visitors: R. Michael Rich, UCLA

December 13th-15th, 2017. 
 
Michael Rich is research astronomer at the UCLA. He works on the subject of “Galactic archeology” – the ages, chemistry, kinematics, and structure of stellar populations at the present epoch (the “fossil record”) as a constraint and primary source of information on theories of galaxy formation and evolution. I use data from Keck and HST to address these programs. These data are complementary to the inferences drawn by study of the distant Universe; a successful theory of galaxy formation/evolution must satisfy constraints from both the fossil record and the distant Universe. My participation in the Galaxy Evolution Explorer (GALEX) science team has opened up a new subject area, galaxy evolution from z=0 to 1. I am PI of the BRAVA and Blanco DECam Bulge Survey programs, and operate a special purpose 0.7m telescope to study low surface brightness dwarfs and halos around nearby galaxies.