Galactic

Members

Members that collaborated to generate this roadmap: 

Laura Chomiuk (NRAO lchomiuk@aoc.nrao.edu )

Primary subgroup contact:

to be appointed

Subgroup MAF engineer:

to be appointed

 

Subgroup Primary members

  • David Kaplan - University of Wisconsin Milwaukee
  • David Nidever - LSST
  • Alexandre Roman-Lopes - Universidad de La Serena

Subgroup Secondary members

  • Marcel Agüeros - Columbia University
  • Eric Bellm - Caltech
  • Howard Bond - Penn State
  • Marcio Catelan - Pontificia Universidad Católica de Chile
  • Laura Chomiuk - Michigan State
  • Geoff Clayton - Louisiana State
  • Victor Debattista - University of Central Lancashire
  • Rosanne Di Stefano - Harvard-Smithnonian CfA
  • Suzanne Hawley - University of Washington
  • Zeljko Ivezic - University of Washington
  • Vicky Kalogera - Northwestern University
  • Knox Long - Space Telescope Space Institute
  • Adam Miller - LSST
  • Hakeem Oluseyi - Florida Institute of Technology
  • Abi Saha - NOAO
  • Keivan Stassun - Vanderbilt University
  • Stephen Ridgway  - NOAO
  • Poshak Gandhi - UK 
  • Rafael Martínez-Galarza - Harvard

 

Roadmap Outline

Science Goals?

Stellar science of all time domain kinds (YSOs, symbiotic stars, LBVs, novae, stellar mergers, transiting planets, microlensing, pulsating stars, X-ray binaries, cataclysmic variables, Galactic supernova)

What goals can be achieved with baseline cadence, What can we do now, in the next few years (ahem, months)?

To answer both these questions, we need to revisit if we are ok with fewer visits to the Galactic plane and bulge (as planned for in LSST baseline cadence; fewer visits compared to the majority of the sky in the WDF survey). Naively, most of our science would benefit, or in some cases, ''require'' observations in the plane and bulge (e.g., Gould 2013, arXiv 1304.3455). To do this:

  1. Generate a library of light curve templates  (for YSO, symbiotic star, LBV outbursts, novae, stellar merger events, microlensing), and exploit the periodicity recovery work of the stellar members (for transiting planets, pulsating stars, X-ray binaries, cataclysmic variables, symbiotic stars).
  2. Consider how the results of the baseline transient/periodicity recovery metrics are affected by crowding in the plane and bulge. : - With published models of the Galaxy, it should be relatively straight forward to estimate how star counts (above a certain apparent mag, neglecting extinction) vary with Gal latitude and longitude. : - We then need to be able to translate estimates of crowding into impact on detection limit and photometric precision. :: – I am not sure how to do this step; perhaps CatSim already has many of the necessary tools? :: – Talk with the Milky Way Collaboration folks who have been thinking about similar issues (Britt, Clarkson, McGehee, Strader) to see if they've made progress. : - Microlensing surveys of the bulge (e.g., OGLE, MOA) might be good sanity checks on these crowding estimates.
  3. Consider how extinction will a) change these crowding estimates and b) affect our sensitivity. : - Estimating these effects should be relatively simple in regions of the Galaxy where there have been reddening-as-a-function-of-distance maps published (hopefully such maps exist for most of the Gal region, at this point…) : - Microlensing surveys of the bulge (e.g., OGLE, MOA) and VVV in the plane might be good sanity checks on these crowding estimates.
  4. Estimate what fraction of a population of interest (e.g., transiting planets) currently dwells in the Galactic plane/bulge (where baseline cadence yields reduced number of visits). This could be difficult to estimate for transients, as transient surveys have typically avoided the plane and bulge in the past. : - OGLE/MOA, however, have covered the bulge, and have uncovered some very interesting transients. We can use this as a sanity check. : - ASAS-SN has just begun regular coverage of the southern Galactic plane and bulge. While this survey has ''very'' different characteristics for LSST, it should help us start characterizing transients in the plane; once we understand the population of bright Galactic transients, we can extrapolate to the fainter population. : - VVV, PTF also have Plane holdings that can be studied.
  5. Consider the most effective changes that might be made to cadence. A deep drilling field in the bulge? Rolling cadence? : - Consider what new science LSST contributes over e.g., OGLE. :: – OGLE/MOA don't have multiple filters; colors (in grizy) can be very useful for distinguishing classes of sources. : - Consider that we might want multiple filters in the same night for e.g., microlensing. : - Consider that we might want to drop e.g., the u band in the plane/bulge.