2019 SB Gaia Sprint

pitch slides

KITP — 2019 March 25

Adrian Price-Whelan (Princeton)

plan to do:

  • Infer true spatial (on sky) density structure of GD-1
  • Improve phase-space models of known stellar streams (e.g., GD-1, Pal 5)
  • Confirm / re-discover some other “known” streams

want to learn:

How to construct a very specific selection function in the GD-1 footprint

will bring:

Expertise in Python/Astropy; Gaia data access and use; galactic dynamics and practical tools; stellar streams; Bayesian inference

want to discuss:

Stellar populations of globular clusters vs. ultra-faint dwarf galaxies; dynamical inference / dark matter; star / globular clusters

Eugene Vasiliev (Institute of Astronomy, Cambridge)

Want to do:

  • use mixture models in parallax+PM+colour space for membership selection
  • search for extended structures around star clusters
  • build dynamical models of star clusters using Gaia+other data(?)

Want to learn:

  • how to find and access other sources of astronomical data besides Gaia

Can share:

  • how to cope with systematics in Gaia astrometry
  • galaxy modelling framework Agama: potentials, actions, dynamical models...

Alice Quillen University of Rochester, Rochester NY

What I want to do:

    • Look for kinematic patterns associated with recent star formation.
    • Improve models for the stellar phase space distribution function that are sensitive to relaxation and resonance

What I want to learn:

    • How to create and work with nice databases of stars

What I bring:

    • Multidisciplinary approach to dynamics modeling, dynamics theory and particle based numerical simulation. Javascript, python, rebound

What I want to discuss:

    • How to create a better 3D and time dependent model Milky Way
    • Classification projects for future large data sets

Lorenzo Rimoldini (University of Geneva, CH)

What I want to do:
1. Classify variable objects without time series: how far can we go?
2. Any
δ Scuti or SX Phoenicis fans to validate the Gaia DR2 candidates?
3. How to best exploit the public time series of
unpublished variability classes?

What I want to learn: complementary data sets; streams; local dark matter density

What I bring:
1. Gaia DR2 variable stars + Classification of high-amplitude pulsators
2.
How to access, crossmatch, and get started with the Gaia DR2 data
3. (Semi-)supervised classification and all what is needed to make it work

What I would like to discuss: variability phenomena; unsupervised classification; quasars; gravity

Zhen Yuan (Shanghai Astronomical Observatory)

plan to do:

  • Finding tails of existing GCs
  • Dynamical Evolution of GCs in the MW

What I bring::

A new clustering method StarGO based on self-organizing-map (unsupervised neural network learning)

Applications: Substructures, Star Clusters, Any Clustering Projects

Example:

Member Identification

For NGC 5824

want to learn:

  • Statistical tools (e.g. non-parametric way to decompose multiple Gaussians)
  • A variety of ways to download Gaia data
  • Mock MW from Latte Simulations

want to discuss:

  • Archeological Fossils: Dwarfs & GCs
  • What can we learn from abundances?

Giuliano Iorio

  • Look for halo structures in phase-space using RRLs
  • RRLs around GCs, RRLs in known streams

RRLs in Pal-5 stream

(Institute of Astronomy, Cambridge)

RRLs around M5

4 Rt

Want to do:

Want to learn:

Ask me about / What I bring:

Want to discuss:

  • Methods to estimate the phase-space density
  • Clustering methods / Associate stars to known GC/Sats/streams

  • MW stellar halo
  • RRLs in Gaia

(I bring catalogs of all RRLs classified in Gaia DR2 with additional information)

  • (non cosmological) N-body simulations

(I bring catalogs of an LMC-like destroyed in the MW, credit D. Erkal)

  • Gaia selection function / completeness
  • How to find shells in the MW halo
  • Can we improve distance estimate for RRLs?

Timothy Brandt
UCSB

  • Want to do: calibrate uncertainties for the medium/faint end of Gaia astrometry: Tycho, WFPC2? ACS?
  • Want to learn: how else can we understand Gaia uncertainties and systematics?
  • What I bring: Cross-calibration of Gaia DR2 to Hipparcos (HGCA), fitting orbits with the HGCA, RV, imaging
  • Want to discuss: how can we get the best handle on spatially correlated systematics, external uncertainties?

P~100-400 years

Paolo Tanga - Observatoire de la Côte d’Azur

What I want to do:

    • Exploit ~200 million asteroid positions reduced with pre-Gaia catalogs
    • Optimize my brand new approach to correct zonal errors for those catalogs
    • Study the results and start writing an article!

What I want to learn: write better ADQL queries, launch python parallel threads, and all that you can share about systematics in ancient catalogs.

What I bring: Solar System data expertise. Zonal error corrections for ~3000 asteroids, ~20 catalogues. Independent cross-match approach.

What I would like to discuss: Spatially correlated errors. Clustering algorithms for multi-dimensional data. Good beers.

Larry Widrow Queen’s University

Want to do: Apply methods such as Gaussian process regression to Gaia data to build models for the phase space DF.

Want to learn: Better methods for GPR including application of sparse GP to problems in 3-6 dimensions and with observational errors.

What I bring: Preliminary success modelling 3D velocity field via GPR. Familiarity with GPy. Have also worked on building equilibrium disk models and embedding them in cosmological halos.

What I want to discuss: Theoretical underpinning of phase space structure in stellar DF and other methods to analyse both data and simulations.

Alexa Villaume (University of California Santa Cruz)

What I want to do:

What I want to learn:

E-IRTF

What you can ask me about:

SQL databases

Stellar population

synthesis models

  • Cross-match E-IRTF library with Gaia
  • Normalize spectra to Gaia photometry
  • Infer luminosity for each E-IRTF star in manner similar to Hawkins et al. 2017

How to choose informative priors when using the parallax measurements

Use Gaia to turn the E-IRTF stellar spectra library into new SPS models

Kathryn V Johnston (Columbia University/CCA)

DO
dynamics-driven data analysis of PS-spiral

LEARN
prior work and best data for this
python tips and toolkits

BRING
direct experience in prehistoric times

DISCUSS
anything and everything

Images from Aaron Tran (Columbia)

Andy Casey (Monash)

What I want to do >> use eclipsing binaries to translate excess astrometric noise to tangential motion, and estimate inclination angles for non-eclipsing binaries

What I want to learn >> is the distribution of inclination angles isotropic?

What I bring >> Zen. My time (for your Sprint problems). Experience in data analysis, some knowledge about stars

What I’d like to discuss >> astrometry >> (other things….) >> thoughts about next Gaia data release

Lauren Anderson (Flatiron Institute)

What I want to do: apply our method for modeling a 3D dust map to real data, profile the python code to minimize compute time, sprint with Juna

What I want to learn: data viz with yt (3d rendering and sim reconstruction), limits of GP method with real data, more intuition for how approximate GP methods work

What I’d like to chat about: interpreting structures in a 3D dust map, including velocity in the dust map, non-parametric representations of galactic potentials, inference of the MW halo shape/accretion history from stellar streams, structures in the CMD, modeling and interpreting the phase space distribution function of stars

What I bring: GP 101 description, data-driven models, curiosity and optimism

Sarah Pearson

Credit: Eilers & Hogg

Gaia/APOGEE

v_r vs v_phi correlation

What I want to do:

Re-compute Eilers’ plot for galactic bars formed through two different scenarios:

  • In-situ (E. D’Onghia’s simulations)
  • Sagittarius impact (C. Laporte simulations)

What I hope to learn:

How long is the Milky Way’s Galactic bar?

How did it form? (optimistic question)

Which orbits support the bar? (using APOGEE/Gaia 6D info)

What can we learn about the bar from APOGEE metallicities?

You can ask me about:

- Galactic dynamics/the Galactic bar

- Orbit integration

- Using Price-Whelan’s Gala package

I’d like to chat about:

- APOGEE selection function

- The Galactic bar in general

Flatiron Institute,

Center for Computational Astrophysics

Luis Quiroga-Nuñez (Leiden Observatory/JIVE)

  • Cross-matches at different λ
  • Variability for evolved stars.
  • Galactic structures
    characterization (arms & bar)

  • Radio astrometry at 1μas
    resolution.
  • Experience generating
    simulated astrometric data.
  • Radio data that complements Gaia results in the GP
  • How variability can be obtained from Gaia ?
  • How extinction maps are used
    over Gaia data?
  • Generate MLE to test the Gaia
    limits

  • Members of stellar association
  • Synergies between astro-
    metric campaigns at different λ
  • Stellar population across the GP
  • Future missions in IR?...plausible?

What I want to do

What I want to learn

What I bring

What I like to discuss

Jason Hunt (Dunlap Institute - Toronto)

What I want to do: Explore the non-axisymmetric & disequilibria structure in the Gaia data

What I want to learn: How to differentiate between signatures of bars/spirals/external perturbers

What I bring: Dynamical Galaxy modelling methods / knowledge; N-body, Test particle, Action-Angle (and models themselves), with various bars+spirals

What I’d like to discuss: Reconciling long/short bar evidence, I don’t mind who’s right, I’d just like to know!

Andrew Wetzel (UC Davis)

to do

  • understand origin (and lack thereof!) of alpha/Fe bimodality in Latte simulations, connection with stellar kinematics (and ages), test this formation scenario with Gaia++
  • convince you to use our (really Robyn’s) Ananake synthetic Gaia DR2 catalogs from our Latte simulations

to learn

  • how better to compare kinematics, abundances, and ages from Gaia + APOGEE + ??? against simulations

bringing/sharing

  • Ananake synthetic Gaia DR2 catalogs and full snapshots of Latte simulations (i.e. I am happy to point you in Robyn’s direction)
  • sarcasm

to discuss

  • joint analysis of abundances + kinematics + ages

Interests

  • Galactic/DM dynamics
  • Secular evolution/kinetic theory
  • Impact of LSS on galaxies

Would like to learn more about

  • GAIA’s constrain on DHs
  • Who wins, when, where in driving galaxies’ fate?

What I bring

  • Understanding(?) of LSS + secular. dynamics

Do discuss

  • What can be done with GAIA streams/ridges?


Happy to work with anybody interested...

What I want to do

  • Modify kinetic theory for streams
  • Map ridges in Gaia coordinates
  • Convince people quasi-linear theory rocks

Patrick LaChance

What I want to do:

  • Disentangle the qualities of the kinematic background in the solar neighborhood from the nearby clusters

What I bring:

  • I bring a clustering algorithm (SNN) that can group stars together based on a variety of attributes (position, velocity, chemistry, etc.) that was developed in our group.
  • I bring some data structures and analysis experience from my CS background.

What I want to learn:

  • I want to learn about the kinematic features of our solar neighborhood, and spiral galaxies in general.
  • I would like to learn the ages and metallicities of the clusters in the solar neighborhood to differentiate them from the background

University of Wisconsin-Madison;

4th year undergraduate student working with Elena D’Onghia

Alexandra Borukhovetskaya University of Wisconsin - Madison

undergraduate student working with Elena D’Onghia

What I want to do:

I am interested in understanding the Arcturus moving group - its members and origin. I am hoping to be able to rebuild the group so that I may argue for either in situ or extragalactic formation.

What I want to learn:

Ages and metallicities of known Arcturus members as well as other clustering techniques.

What I bring:

Clustering algorithm (SNN) developed in our group, previously used for kinematic and chemical clustering for globular clusters and now modified for clustering in Gaia data - proper motion, ra, dec, and parallaxes.

Elena D’Onghia (University of Wisconsin-Madison/Flatiron Institute)

I will work on understanding the formation of moving Pleaides, Coma Berenice (with Patrick LaChance) and on Arcturus moving group (with Alexandra Borukhovetskaya)

I want to learn about ages and metallicities of moving groups and the open clusters

I bring dynamical models with N-body simulations and experience on galactic dynamics

Juna Kollmeier (Carnegie Observatories)

What I want to do: I would like to produce useful “Gaia Gold Catalogs” for quasars, single stars and white dwarfs. Or something cooler with Anderson. Maybe some BHBs?

What I want to learn: The pitfalls of producing such catalogs; particularly how to best cut the Gaia data

What I bring: broad interests and expertise

What I want to discuss: I will want to discuss anything

Hamish Silverwood

ICC, University of Barcelona

Do:

-Gaussian Process Regression on binned velocity and tracer density data →

-Apply to Jeans Equations to derive force maps and/or disequilibria maps (Δ-Jeans method from Sprint 2018), working with Lauren Anderson & Larry Widrow.

Learn:

Anything GP related. Selection functions.

Bring:

Broad Dark Matter knowledge (indirect, direct detection etc). Expertise in Jeans Modelling. Oscar - brute force tool for binning Gaia data incorporating full uncertainties.

Discuss:

Dark matter. GPs. Future measurements of stellar accelerations with high precision spectrographs & nano-arcsecond astrometry (1812.07581).

VRVR

VRVZ

VZVZ

Harshil Kamdar

Harvard

Plan to do: can angles between very wide co-moving pairs in data (>2 pc) tell us about whether stars are born together?

Want to learn about: hierarchical star formation.

Can help with: the lifecycle of star clusters born in the disk, clustering algorithms.

Would like to discuss: the ISM! And what we can learn about clustered star formation from Gaia.

A simulation of all stars born in star clusters in the Milky Way disk in the last 5 Gyr that includes a realistic potential (bar + spiral + GMCs) and a subgrid model for cluster birth and evolution

Cecilia Mateu (UdelaR, Uruguay)

What I bring:

  • RR Lyrae stuff + Gaia RR Lyrae completeness maps, PyMGC3, Galstreams library - compilation of MW stream footprints

What I want to do:

  • Calibrate MG for RR Lyrae stars as a function of period-shift (location on Period-Amplitude diagram)

OoII RRLs are brighter than OoI:

~0.25mag

= 10% in

Distance

What I want to learn:

  • Statistical tools to deal with error systematics & correlations

What I want to discuss:

  • New analytical models for the disc’s density profile to replace double exp+flare+warp

Anthony Brown (Leiden Observatory)

What I want to do

  • Build a “Gaia for beginners” catalogue, intended for use in, e.g., astronomy education (thanks Juna for suggesting this!)
  • Gaia DR2 sub-sample cleaned from the nasty bits, documentation, warnings on limitations

What I want to learn

  • Can the “phase spiral” really be explained as due to moving groups (arXiv:1903.08325)?

What I bring

  • Gaia expertise: all aspects of the data, quality filtering, archive access, ...

What I want to discuss

  • Your thoughts on future Gaia data releases
  • How to preserve sufficient likelihood information in long term Gaia archive
  • Gaia selection function: your inputs on a good proposal to fund this effort
  • Uncertainties/systematics: how will these affect cross-calibration of other/future surveys against Gaia?

Christina Eilers (Max Planck Institute for Astronomy)

you can ask me about: distances to APOGEE red giant stars, Gaussian processes, the Milky Way’s circular velocity.

sprint idea: find, map & model non-axisymmetric features of the Milky Way.

I hope to learn about: Galactic bar, spiral arms, how to install galpy & calculate actions.

Hans-Walter Rix Max Planck Institute for Astronomy, Heidelberg

you should ask me about: SDSS-V
the perfect spectroscopic match to Gaia...

seeking collaboration on Gaia (DR2) as a time-domain survey: DR2 provides rms variations in flux, astrometric wobble, and vlos

(non-)variable WD candidates/contaminants

rms fractional flux variation in G

and their light-centroid wobble

Kohei Hattori (University of Michigan)

to do

  • Identify chemo-dynamical substructure in the stellar halo using clustering algorithms
  • Estimate the shape of dark matter halo using hyper-velocity stars
  • Use orbits of runaway stars to identify their natal star clusters

to learn

  • Clustering algorithms
  • Density distribution of young stars (<10Myr) in simulations.
  • Chemistry/age of known young massive clusters (e.g., Westerlund 1).
  • Basics on photometric metallicity

  • Why sometimes, two mathematically equivalent ADQL queries take very different times.
    • (E.g., “Select ra from AAA where (ra < 10)” and “Select ra from AAA where (ra - 0.5 < 9.5)”)
    • Any tips for reducing the ADQL query times.
  • Does anyone use astroquery? Is there any ways to run ADQL queries other than Gaia archive?

to bring

  • Knowledge on hyper-velocity stars / runaway stars
  • Practical use of AGAMA code

to discuss

  • Gaia Sausage / Disc substructure (e.g., Hercules stream)
  • Any bold ideas using Gaia data

Siddharth Mishra-Sharma (NYU)

What I want to do:

  • Understand collective effect of Galactic dark matter substructure on stellar velocity/acceleration fields (dynamical + lensing-induced)
  • Look for this pattern in Gaia DR2

What I want to learn:

  • Working with Gaia data!
  • Estimators and techniques to look for structure in 3D vector fields, accounting for uncertainties (e.g., extensions of 2-point correlations)

What I bring:

  • Background in astrophysical signatures + particle physics properties of dark matter
  • Experience in writing fast Python code

What I’d like to discuss:

  • Particle physics implications of DM substructure (population) measurements

Substructure lens-induced...

… velocity field

… acceleration field

Jackie Faherty, American Museum of Natural History

Do: Figure out what the end of the main sequence in Gaia looks like and find new objects (young especially!)

Learn: About hypervelocity stars in vtan space

Bring: The end of the main sequence and science visualization

Discuss: Visualizing our data!

Sihao Cheng Johns Hopkins University


What I want to do >> white dwarf H-R diagram

  • Explain the Q branch
  • WD-WD merger rate

What I want to learn >>

optimal quality cuts; selection function; dust within 250 pc

What I bring >>

  • white dwarf knowledge:

cooling, merger, spectra, ...

  • experience in DR2 light-curves (effect of extended sources)
  • scanning directions of Gaia

What I’d like to discuss >>

  • Gaia selection function
  • Gaia-Panstarrs cross-matching
  • bifurcation of Sagittarius Stream
  • spiral arms in stellar mass / gas

...

May Gade Pedersen (KU Leuven, Belgium)

Plan to do:

  • Determine luminosities of pulsating stars
  • Search for stellar clusters w. EMSTOs and fit isochrone clouds

Want to learn

  • Application of Gaia astrometry and photometry to stellar clusters
  • Cluster membership verification

Ask me about

  • Asteroseismology/seismic modelling of pulsating (massive) stars
  • Internal mixing and impact on stellar evolution and surface abundances

Johnston+2019

Victoria Antoci

Isochrone Cloud

Heidi Newberg (Rensselaer Polytechnic Institute)

plan to do:

Explore the shell structure in Virgo and related halo substructure

want to learn:

Is the shell structure in Virgo the same as the

Gaia-Enceladus/Gaia-sausage merger and how old is

that structure?

bringing:

Expertise in structure of the Milky Way halo and disk.

want to discuss:

How do we fit N-body simulations to Milky Way shell

structure?

David W. Hogg
(NYU) (MPIA) (Flatiron)

What I want to do >> Map non-axisymmetries in the disk with red-giant stars.
>> Dynamically model the GD-1 spur.

What I want to learn >> How to classify stellar variables using Gaia noise information.

What I bring >> Expertise in computational data analysis, linear algebra, Bayesian inference, model building, MCMC. >> Knowledge about SDSS, BOSS, APOGEE, HARPS, Kepler, and Gaia.

What I’d like to discuss >> Hierarchical models. >> The Gaia likelihood function.
>> Mapping the dark matter. >> Chemodynamics. >> Binary stars.

Jason Sanders

(Institute of Astronomy, Cambridge)

What I want to do - 3d bulge (chemo-) dynamics with Gaia RVS M giants. Photometric metallicities → distances.

What I want to learn - kinematic differences between metal-rich & metal-poor populations across bulge.

What I bring - knowledge on ages/distances from Gaia+spectro, action-angles, streams, bar/bulge.

What I want to discuss - 3d extinction mapping, photometric metallicity/ages, RVS selection fn, bar’s impact on SN kinematics.

Li et al. 2016

Metallicity

WISE colour

Borja Anguiano - University of Virginia

What I want to do: Characterize the kinematic signature of the Galactic stellar warp using APOGEE and Gaia data-sets.

What I want to learn: I noticed that recent works are pointing out new ways of using Gaia flags. I would be interested to have a discussion with Gaia experts about it.

What I bring: Knowledge and experience working with APOGEE, GALAH and RAVE data, this can be useful for this meeting.

What I want to discuss: Stellar multiplicity using different RV visits in RAVE.

Sukanya Chakrabarti (RIT)

Plan to do:

  • How do MW satellites affect the gas & stellar disk ? Including new satellites discovered by Gaia

Expertise:

  • SPH & test particle

simulations, galactic dynamics, variable stars

Want to discuss: happy to discuss anything!

Levine, Blitz & Heiles 06

Chakrabarti & Blitz 09

Josh Simon (Carnegie Observatories)

What I want to do: Photometrically select metal-poor stars by combining broadband colors from Gaia and other all-sky surveys

What I want to learn about: Efficiently cross-matching large catalogs, spectroscopic surveys covering bright (V<14) stars

What I bring: Knowledge of dwarf galaxies and stellar streams (in Gaia and elsewhere). Beginner’s ability to model orbits with galpy.

Other things I want to talk about and/or work on: Dwarf galaxies, stellar streams

1962 version:

Wallerstein (1962)

2019 version?

Ellianna Schwab Abrahams (UC Berkeley, CTDI)

Plan To:

  • Search for anomalous RV measurements using ensemble learning
  • Predict RV measurements for stars without measurements
  • Also very interested in the DR2 Time-Series Catalog and variable star classification

Hope to Learn:
Systematics in the Gaia RV Catalog Edge detection and clustering methods

Bringing/Ask me About:
ADQL Queries Database Crossmatching Representation ML Time Series Featurization

Want to Discuss:
Gaia in the time domain, in DR2 and future DRs Detecting variability using static data

Morgan Fouesneau

What I want to do this week

  • Dynamics of M31 HII regions using biased Gaia astrometry
  • Star cluster properties accounting for small field correlations

What I would like to learn this week

  • Estimating Gaia’s small field of view correlations
  • Feedback on Gaia mock and GDR2.
  • Crossmatching catalogs including SED information

I Can help with

  • Gaia data, crossmatch & data query helpdesk
  • Gaia Mock / Gaia classification & APs
  • GDR3 BP/RP spectra

Max-Planck Institute

for Astronomy

fouesneau@mpia.de

@mfouesneau

LV in gas
[sim]

Interested in:

  • Large scale [G/g]alactic structure. Impact of spirals/bars/companions on ISM/SF processes.

Aim to do:

  • Look at galactic scale velocity fields, how they compare to sims. with different asymmetries/underpinning physics.

Specific knowledge of:

  • Hydro+N-body simulations of galaxies, ISM physics.

Would be keen to know more about:

  • Any aspect of the obs. data really
    (not touched it before!), phase spirals,
    models people are desperate in need of.

...What I don’t want to talk about:

  • Brexit. Please... just let it end.

Do ISM features align 
with any stellar pops?

ISM in
a spiral

Makes some stars...

Alex Pettitt 


?

Kareem El-Badry (UC Berkeley)

Ideas:

  • What’s going on with wide binary luminosity ratios?
  • Hardening of close binaries in hierarchical triples
  • Test MOND with wide binaries

Bring: binaries, white dwarfs, cosmological simulations, enthusiasm, short attention span

Learn: how to use Gaia as a time-domain survey

Plan to do: Look at known streams in Gaia - measure proper motions, map density, look for extensions in RR Lyrae

Want to learn: More about Gaia systematics, RR Lyrae, reliable density mapping of streams

Bringing: Experience working with DES data, cross-matched dataset, tools for working with streams, experience with stream detection, photometric filtering, proper motion measurement

Want to discuss: Dark matter constraints with streams, differences in globular cluster/dwarf stream populations

Nora Shipp (UChicago)

Emily Cunningham (UCSC)

What I want to do: Look for spatial variation of kinematic properties in the halo with RR Lyrae

What I want to learn: Modeling Gaia systematics; computationally efficient Bayesian inference methods for use with large datasets

What I bring: Expertise in proper motions with HST; spectroscopic analysis; Bayesian inference (incl. hierarchical and mixture modeling)

What I’d like to discuss: Methods for combining multiple datasets; chemodynamics; data-model comparison tools

David Mykytyn (New York University)

What I want to do: *joint with Alex Malz (NYU; he is remote due to impending thesis defense but will Skype in when possible)

  • Improve HR Diagrams for open clusters by identifying and correcting double stars, with the goal of creating a fully probabilistic model for HRD

What I want to learn:

  • A lot more about good models for HRD and also some stellar models that could be combined?
  • Stuff about open clusters? -> What generates the HRD for clusters

What I bring:

  • A lot of knowledge about Gaussian Processes, especially for time-series analysis. Some crazy ideas about using GPs to speed up monte carlo, or even to get better information out of simulations (keywords: Multifidelity Monte Carlo, metamodels/emulators/simulators/etc.)

(Want to get at what 1801.08547 marginalized over)

[Widmark, et. al 2018]

(First stab at PGM)

Ana Bonaca

Center for Astrophysics

Harvard & Smithsonian

Do: constrain the orbit of a possible perturber of the GD-1 stream based on the kinematics of the perturbed region

Bring: Python3 API for C, expertise in the detection and modeling of structures in the stellar halo
Discuss: dating accretion events based on their structure in the space of conserved orbital properties

> Discuss:
- (Passively): DF modeling in action-angle space; inferring MW dust maps with DR2 + MA, age-abundance relations, realistic pipeline for time-series data; zoom-in simulations;

- (
Passionately): outline of a SOTA analysis, hierarchical inference, banish closed-form likelihoods?

(Brown U.)

> Intend to:
- (Warmup) DR2-APOGEE/SDSS x-matched data-sets to study chemo-dynamic properties of velocity ‘substructure’ (h/t: Myeong+’18, TCR’18).

- Develop criteria for qualifying stellar population in a given volume patch as phase-mixed (h/t: BMH’09).

> Experience:
- with DR2 data and selection function based on gaia_tools (Bovy’16);

-
particle physics: indirect and direct DM detection; cooling rates for dissipative DM.


- (Audaciously): Explore disequilibria with a semi-analytic forward modeling approach using simulations; toy n-body code that includes DM self-interactions.

Semyeong Oh

Institute of Astronomy, Cambridge

I am doing:

kinematic modelling of a cluster

- evidence beyond small (isotropic) dispersion?

I want to learn about:

    • stellar binaries and clusters
    • hierarchical inference and clustering
    • future data

I bring experience with:

Gaia data access and exploration and

making interactive visualizations

Joel C. Zinn

Ohio State University

What I want to do:

Explore TESS-K2-Gaia synergy

What I want to learn more about:

Binaries in Gaia

Gaia parallax systematics

I bring experience with:

Parallaxes beyond ~2-3kpc with red giants, asteroseismology, stellar models, APOGEE, Kepler, K2

Chervin F.P Laporte (University of Victoria / CITA)

DO 1) Finish paper from last year’s Sprint. 2) Test+Map PS-spiral beyond 10 kpc without WEAVE or 4MOST with RC and a model to generate RVs complementing 5D data.

LEARN Bayesian inference methods, data driven techniques, adaptive smoothing/filterning methods, AGAMA.

BRING My pre-Gaia DR2 N-body models of Sgr impacting disc (free data). Useful for anyone doing disc-kinematics/bar kinematics? Familiar with studying kinematic substructure in SN, i.e. happy to help people (e.g. Elena’s team on Arcturus) if I can/it’s cool with y’all.

DISCUSS
Existence of moving groups is not a physical explanation for the origin of the PS-spiral.” Happy to discuss/philosophise with Anthony Brown (maybe do a project?). Analogy: If I put re-assemble KFC chicken pieces (drum, breast, wings) into something looking like a chicken it doesn’t mean that KFC explains why chickens exist.

Pre-Gaia simulations

Gaia DR2

??????????

??????????

Andreea Font (Liverpool John Moores U., UK)

What I want to do:

Look for substructure signature in the Solar neighborhood using various tracer stars.

Compare with results of cosmological simulations. Think about implications for dark matter detection.

What I want to learn:

Combining different catalogues (Gaia, RAVE, APOGEE).

Modeling Gaia systematics.

Knowledge of:

hydro-dynamical simulations, chemo-dynamical models of the Milky Way and dwarf galaxies.

Robyn Sanderson

UPenn/Flatiron

ananke.hub.yt

Doing: evaluating basis-expansion models of the Latte halos for orbit studies, prep for public release of models

Learning: how well we need to represent the MW to study its orbit structure; what else people want from mock observations

Sharing: the ananke mock catalogs, dynamics expertise generally

Philip Chang (University of Wisconsin - Milwaukee, Flatiron Institute)

What I want to do: See what everyone is up to; extract physics from test particle simulations.

What I want to learn: am currently GAIA curious - ready to take the next step.

What I bring: Expertise in theoretical and computational astrophysics; some experience in test particle dynamics; a bit more in SPH/Moving-mesh/Eulerian hydro.

What I want to discuss: Phase space mixing of stars, perturbation theory, etc.

2019 SB Gaia Sprint pitch slides - Google Slides