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2018 NYC Gaia Sprint wrap-up slides

2018 NYC Gaia Sprint wrap-up slides

90-ish authors; presented on 2018-06-08 at the Gaia Sprint

David W Hogg

June 08, 2018
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  1. 2018 NYC Gaia Sprint
    wrap-up slides

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  3. Matt Wilde UW

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  4. Lauren Anderson Flatiron

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  5. Sergey Koposov
    Did: Talked a lot, learned a lot, looked at
    streams/binaries/substructures/RRlyrae,
    Got distracted by ‘weird RRlyrae’.
    Didn’t quite do what/as much as I was planning to do.
    Great meeting -- thank you!

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  6. TLDR: “this looks cool” ⇒ “where am I?!” ⇒ “this looks strange”
    Learned
    - should have known: Can’t look for GW in DR2
    (need residuals from epoch-astrometry, not motion fits)
    - not surprising: Gaia doesn’t share scanning solution
    (but it’s not too hard to extract; thanks @SihaoCheng!)
    - surprise: spin-2 spherical-harmonics are our friends
    (and emcee can calculate them quite well!)
    Accomplished
    - Many additions to simulated GW-detection pipeline
    - Realish scanning law for “observations” (almost done)
    - Incorporate model of Basic-Angle modulations (``)
    - Use real DR2 magnitudes and uncertainties
    - `` DR2 proper-motions, and positions
    Luke Zoltan Kelley
    [email protected]
    Harvard CfA ⇒ Northwestern CIERA
    Gaia Astrometric
    Gravitational Wave
    Detection
    Thanks So Much!!
    CCA, SOC, GAIA &
    Sprint Attendees

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  7. Thanks to Alcione Mora, Hans-Walter Rix, Jonathan Gagné and Jackie Faherty

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  8. 1. Distribution of q (mass-ratio) of unresolved binaries (m1<1 Msun) as a
    function of m1 and [Fe/H]
    2. (with Xiangxiang Xue) Identify new OB associations
    Chao Liu (National Astronomical Observatories, CAS)
    p(q|m1) p(q|[Fe/H])
    Single Single
    New spiral
    arm?
    q q

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  9. Gabriel Torrealba
    ASIAA
    - Used RR Lyrae as tracers of satellite
    galaxies
    - Learned a lot from an amazing group
    of people!

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  10. Daniel Michalik ( & )
    Met fantastic people, discussed amazing projects
    Computation of spectroscopic parallaxes (Eilers et al): understood individual
    outliers due to astrometric quality, photometric quality, variability
    Explored the identification of multiplicity from Gaia-DR2 and DR1-TGAS
    ○ Goals: TGAS 2.0, long-period (>25 yr) binaries, dynamical masses from orbital fits
    ○ People involved: Brandt, Faherty, Hernandez, Michalik, Mora, etc
    Intended to confirm/reject kinematic cluster members in chemical space
    ○ Too little overlap with APOGEE, GALAH
    ○ Learned about Hypatia (Hinkel et al.) - to be continued!
    Visiting the Netherlands? Say hi at ESTEC - standing invitation for all sprint participants! Email address is in the running notes of the sprint

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  11. Keith Hawkins (UT Austin)
    Can we measure Eu (r-process) in
    APOGEE spectra?
    A (photometric) metallicity Map of the MW
    w/ N. Hinkel w/ Y. S. Ting
    YS Ting + shows can measure [Fe/H] from
    WISE+Gaia+2MASS+Panstarrs photemotry to ~0.20
    dex (NN, Ting) and (PM, Hawkins)
    HYPOGEE: APOGEE+Hypatia (111 stars)
    [Eu/Fe] in GALAH+APOGEE: -0.14 (0.15 dex)
    [Eu/Fe] in Gaia-ESO+APOGEE: 0.02 (0.18 dex)
    Line identification underway w/ N Hinkel
    Maybe wrong?

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  12. Sanjib Sharma
    (University of Sydney)
    ● I computed the anisotropy profile of the stellar
    halo using BHB and K Giants from SEGUE
    (Xue et al.).
    ● I used a non-parametric Bayesian scheme,
    along with a model for outliers. I take into
    account uncertainties in radial velocity, proper
    motion and distance. The model had about
    120 free parameters.
    ● While most N-body simulations suggest outer
    stellar halo to be radial ( >0) we find the MW
    halo to be non radial ( <0).
    Bullock & Johnston 2005 (Kafle et al. 2012)

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  13. Natalie Price-Jones (UToronto)
    What worked:
    - Developing normed
    distance metric for
    patchy/uncertain data
    - Chemical clustering on
    APOGEE spectra/GALAH
    abundances in Gaia
    overlap
    - Abundance trends in R, z
    with Gaia positions
    What didn’t:
    - Verifying clusters with
    chemical space alone
    - Distinguishing open
    clusters in chemical
    space with DBSCAN
    Next steps/new ideas:
    - Implement FOPTICS in Python (thanks: Joris de Ridder)
    - Look for chemistry of nearby young associations
    (thanks: Jonathan Gagné)
    - Action-angle space clustering (thanks: 4th floor library)

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  14. Francisca Concha-Ramírez
    Leiden Observatory ❄
    ✅ Learned to better represent my (simulated) open clusters to be
    compared with observational data
    ✅ Used Boquan Chen’s clustering algorithm, adapted it for my simulations
    ✅ Learned about arcane topics such as parallaxes and proper motions
    ✅ Talked to a lot of people, got new ideas for my project
    ✅ Preached about AMUSE
    ✅ Tweeted a lot #GaiaSprint
    Did not feel judged about my usual excessive emoji use
    ✅ Wrote a script to run an open cluster moving through the galaxy
    and interacting with giant molecular clouds…
    ❌ ...to see if it would yield something similar to Semyeong’s object.
    It didn’t
    http://francisca.cr
    @franconchar
    franciscaconcha
    Let’s a k u p lu r !✨

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  15. Tried to do: Classify QSOs/BHBs/WDs using Gaia-GALEX-WISE.
    SDSS spectroscopic training set of 4,000 BHBs ---> Gaia catalogue of 400,000
    Needs to be cleaned (a lot), but can be used to map halo in proper motions!
    Douglas Boubert (IoA, Cambridge -> Magdalen College, Oxford)
    What is next:
    Map these stars in velocity, add in GALEX
    and WISE, go to lower latitudes, extend to
    classifying quasars as well.
    What I learnt:
    1. Only write code if you are sure that it
    isn’t in Bovy’s back-catalogue.
    2. You are only as good as your internet
    connection to the Gaia archive.

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  16. Hans-Walter Rix (MPIA)
    Plan: finish 1 paper, start 2 papers.
    Result: finished 0, sniffed out or co-started >5.
    I am happy
    Learned:
    ● that global kinematic disk maps can be made!
    (from Inno, Eilers, Hogg, ..)
    ● how the disk heats (from Ting)
    ● how to find massive stars (from Cantiello,Mora)
    ● infinitely more from many others
    Took away: Gaia + Sprinters sowed 1000 scientific flowers.
    Let’s await the bloom
    The gently warping
    young disk
    (courtesy Laura Inno)

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  17. Federica Spoto
    ● Combine Gaia + ground-based obs
    ~ 190 millions of obs with
    their catalogs
    ~ 2 millions of Gaia obs
    How does it work?
    For each observation:
    1. Cross-match
    2. Correction

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  18. Matthew Buckley: Mass through Phase Space
    Goal: calculate the mass of gravitational objects
    by calculating their phase space volume in the
    Gaia data.
    Test this using M4
    Problem: too far for radial position/velocity
    measurements to be accurate.
    But! It’s a spherical system, so just rotate the
    projected positions/velocities (this cannot
    increase the phase space volume).
    I calculate a mass within 10-20% of the
    accepted answer (with caveats)
    Accepted mass
    My best-fit mass
    Range of masses using range of
    concentration parameters of globular
    clusters
    Thanks to Katelin, Lina,
    Hamish, Oren, Colin, Adrian,
    and Hogg for help this week

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  19. Jeans Analysis of the Local MW
    Katelin Schutz, Hamish Silverwood, Oren Slone
    Measurable with DR2
    Unknown
    Radial + Vertical Forces
    And Disequilibria
    X
    R
    X
    Z
    Zero Disequilibria:
    X
    R
    = -K
    R
    X
    Z
    = -K
    Z
    Comparing Populations i and j, extracting time term T
    X
    Ri
    - X
    Rj
    = T
    Ri
    - T
    Rj
    X
    Zi
    - X
    Zj
    = T
    Zi
    - T
    Zj

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  20. Jeans Analysis of the Local MW
    Katelin Schutz, Hamish Silverwood, Oren Slone

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  21. Jeans Analysis of the Local MW
    Katelin Schutz, Hamish Silverwood, Oren Slone
    Outlook:
    ● Performing same analysis on tracers
    with different dynamical mixing
    timescales
    ● Find regions that are relatively in
    equilibrium
    ● Model time-dependent terms
    ● Measure properties of the DM halo
    (triaxiality, radial profile, mass, local
    density)
    ● Measure correlation of DM/acceleration
    with baryonic profile/acceleration
    ● Compare with simulations of various DM
    models
    10-13 km s-2

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  22. 2. DR2 pm compared to TGAS pm -> pm_accel:
    Trying to find accelerating objects
    Wrapping up Gaia Sprint!
    LMC
    4. PSA: Don’t forget radial velocity is in heliocentric
    frame
    SMC
    1. Comoving Objects Collector:
    Group by patches of sky, only take objects with
    low variance on proper motion.
    Insights:
    1. LMC is rotating and spinning
    2. SMC also; but has satellites
    3. I think we can use this to find streams
    3. Lensing: Ken will talk about
    our ongoing analysis!

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  23. Eddie Schlafly (LBL)
    ● Fit photometry of ~50k sources seen in Gaia+APOGEE+PS1+2MASS+WISE
    ● Learned absolute magnitudes as a function of APOGEE spectroscopic
    parameters, reproduced observations to ~10 mmag
    ● New extinction curve measurements with Gaia!

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  24. Kareem El-Badry (UC Berkeley)
    ● Separation distributions
    of wide binaries bear
    imprints of disruption
    and common envelope!
    ● Binary fraction does not
    depend on [Fe/H] for
    wide binaries!
    ● Learned about binary
    evolution, Gaia
    sensitivity limits, white
    dwarfs
    ● Good discussion with
    Badenes, Price-Whelan,
    Rix, Liu, Widmark, Oh,
    Koposov ++
    ● Met many nice people!

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  25. Daniella Bardalez Gagliuffi
    Things I did:
    - Crossmatched spectral binary sample to Gaia for:
    - Understanding astrometric flags (with Richard
    Galvez)
    - Comovers, i.e. triple systems (with Megan
    Bedell)
    - Cleaned 25pc sample way too much so killed all
    binaries
    Things I learned:
    - Tricks and quirks of the Gaia data
    - Brown dwarfs in Gaia too faint to find even fainter
    things around them for now :( Maybe next DR
    - My cleanish 25pc sample is way too clean! Need to
    relax quality cuts. Most importantly, quality cuts
    depend on the kind of objects you’re interested in.
    Thank you everyone!
    astrometric_excess_noise

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  26. Scarlet S. Elgueta
    Inverse BW method: From distance(parallax) -> Radial components (spectroscopy) + Angular

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  27. Chervin Laporte (UVic)
    Refined colour magnitude diagram and proper
    motion selection for the AntiCenter Stream - to
    select targets from MSTO to RGB for stream
    modeling.. Saw that Monoceros and ACS appear
    as “distinct” kinematic components in mul vs mub
    space
    ACS looks very much like the remnant of a tidal tail
    from Sgr perturbation to disc.
    Had conversations with HWR and DH about outer
    disc (perhaps some stars in APOGEE fall on the
    structure or Monoceros - will need to discss further
    when I select all the M-giants in the field). Also
    some conversations with Colin Slater on Anticenter!
    Had conversations with Ron + Hamish about disc
    disequilibrium in simulations and data.
    Had problems with proper motion subtractions in
    the edge of the disc - will have to write own routines
    to figure what is going on. Was hoping to learn
    more about modeling, but will be in touch with
    members. Thanks for the invitation!!!

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  28. Josh Peek – STScI/JHU
    I tried to find the dust around post(-post) AGB stars… and failed to fail... so far?
    I tried a lot of stuff with varying
    levels of stupidity
    ● constructing absolute
    magnitude incorrectly, like 3
    times
    ● selecting post-AGB stars
    from Gaia (hard to tell from
    reddened hot stars)
    ● using catalogs of post AGB
    stars (dust likely way to
    close in & opaque)
    ● trying to use the a_g_val
    (scary systematics)
    I learned about the HRD
    and WD cooling curves
    ~300, d < 1kpc
    Hot WDs
    ~1 Myr past tp
    0.02 mag of reddening ~
    1% decrease in star counts
    Few M⊙
    of dusty
    gas??
    I remain
    skeptical

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  29. Lina Necib, Caltech
    ● Learned a lot!!!!
    ● Played with the completeness function from Ronald Drummel and Jan
    Rybizki.
    ● Failed multiple times at getting the density distribution of the metal poor
    stars (all by myself!).
    ● Joris De Ridder taught me how to query data (now I know that I hate it).
    ● Jackie Faherty and Jonathan Gagne visualized my sample!
    ● Keith Hawkins suggested ways to test the validity of the chemical
    abundances of my sample of stars.
    ● Got faster MCMC code from Lachlan Lancaster.
    ● Discussed new datasets of metal poor stars with Juna Kollmeier.
    ● Discussed the density distribution with Vasily Belokurov.
    ● Talked to the particle physicists: Mariangela, Matt, Neal, Ken, Katelin,
    Oren, and Hamish.
    ● Did not manage to get a decent plot of the density distribution before we
    have to present the wrap up slides.
    R [kpc]
    M_sun/kpc^3
    Slope = ?

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  30. ● Calculated bayesian distances with Kepler zero point
    ● Found extinction probabilities for each star and applied
    these to calculate absolute magnitudes,
    empirical radii and bolometric luminosities
    ● Learned so much about
    dust extinction,
    data validation,
    data storage,
    integers and more!
    ● Great discussions with so
    many people including
    Josh Peek, Eddie Schlafly,
    Boris Leistedt, Alcione Mora, Megan Bedell,
    Jonathan Gagne, Adrian Price Whelan,
    Rocio Kiman + it was lovely to meet everyone!
    Ellie Schwab Abrahams (AMNH, UC Berkeley)

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  31. Rachael Beaton (Princeton & Carnegie)
    ★ Course BP, RP, and G Period-Luminosity Relationship for RR Lyrae
    ○ Use MG = 0.5 mag -- look for paper by Jill Neeley soon.
    ★ Collated 200+ RRL spectra into phase-curves in Temp, log(g), & [(Fe, Si, Al)/H]
    -- We can & will do RR Lyrae Chemistry in APOGEE! (left)
    ○ Bounced it to students at UVa to finish polishing the line list :-).
    ★ Cross Match OGLEIV (Sgr + Bulge) with Berry’s master Gaia RRL Catalog.
    Sgr
    OGLE IV RRL
    ★ Use 1% mean distance to Sgr from
    SMHASH (MIR RRL) an assume that
    the scatter in mag = line-of-sight
    depth. Coarsely, agrees with what we
    get using MIR PL.
    ★ Convert PM to Vtan for each star.
    ★ Remove “bulk” motion (just the PM
    components)
    Super Preliminary

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  32. Jackie Faherty, AMNH

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  33. Eileen Gonzales, CUNY GC
    Subdwarfs with parallaxes Pre-Gaia
    Thing that I did this week:
    ● Completed my catalog of subdwarfs type sdM6 and later
    ● Updated absolute magnitude relations for JHK vs SpT
    ● Started to play around with the sample
    ● Found an awesome spot to work all week!
    Post-Gaia

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  34. Xiang-Xiang Xue NAOC,Beijing
    Credit: B. Pila Díez.

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  35. Neige Frankel (MPIA) -- WORK IN “PROGRESS”
    -- Had the pleasure to meet the authors of my favourite papers
    -- Adapted a radial migration model (##)
    from p([Fe/H], age | R_gal, model)
    to p([Fe/H], age, R_gal | model) → can now predict a density profile.
    to plug in a spatial selection function.
    -- Received tips for APOGEE selection function from Melissa N.
    -- Was stuck for 24h on a 4D integral connecting model predictions to selected
    data, until Dan F.M. pointed out it should be a 3D integral!
    -- Working on a 3D integral.

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  36. David W Hogg (NYU) (MPIA) (Flatiron)
    ● My project: spectroscopic parallaxes with APOGEE and Eilers
    ○ (side conversation: radial-velocity binaries with Price-Whelan and Casey)
    ○ (side conversation: velocity-marginalized parallax likelihoods with Leistedt)
    ● I learned: L1-regularized linear regression is incredible: We beat full spectral
    modeling in spectroscopic-parallax precision, and our data-driven model is
    literally a projection of the spectral (and photometric) data onto a single linear
    basis vector!
    ○ Take that, deep learning!
    ○ Model is interpretable and uncertainties can be propagated; not true for deep learning!
    ● Now we can: Make precise maps of the Milky Way in abundances and
    kinematics.
    ○ (out to 30 kpc from the Galactic Center; much further than red-clump stars)

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  37. Jason Hunt (Dunlap Institute, Toronto)
    Chatted to people about the structure in the velocity distribution, and potential
    causes for it - e.g. Spirals, phase mixing after passage of dwarf / merger.
    Finished this paper
    On (arXiv tomorrow!)
    Then I (mostly) learned actions! (Thanks Wilma & Adrian)
    And, with 4th floor library:
    Action space clustering
    (credit: Natalie P-J)
    Searching for resonance conditions in action
    / angle / frequency space (credit: Ted)

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  38. Vasily Belokurov. Density vs Phase-space density

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  39. Ronald Drimmel [email protected]
    Learned lots. Helped others. Shared data.
    Talked about completeness.
    Found >8400 EHB stars.
    Questions:




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  40. Cicero Lu (JHU)
    ● Giants misclassified (these two
    are 5.7kpc, & 46 kpc away)?
    ● Giant stars hosting sub-Neptune
    planets?
    ● Matthew Wilde told me he also
    see similar stuff for Kepler
    Could there be potential metallicity offset
    between Exoplanet host and non-host?
    Done: X-matched Gaia x K2 x APASS x 2MASS for M dwarfs

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  41. Alcione Mora (ESA-ESAC)
    1. Learnt how people use
    the data
    2. Prepared for ESAC
    Exploration Lab
    3. Done some multiples:
    Hipparcos vs Gaia DR2
    4. Wanted to do more on
    catalogue debiasing
    5. Enjoyed a lot

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  42. View Slide

  43. Stephen Feeney, Flatiron Institute
    What I’ve done:
    Initiated one wild goose chase :/
    Talked to very interesting people \o/
    Downloaded ~10K Gaia Cepheids :O
    Downloaded ~50 HST Cepheids :)
    Moved from Python 2.7→3.6 >:(
    Discovered Astropy’s awesomeness \o/
    Matched all but 6 Cepheids… O.o

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  44. Boquan Chen, UWisconsin-Madison => USydney
    [email protected]
    1. Classification of Orion with 5d information in Gaia 2.Chemo-Dynamical Tagging with
    APOGEE-Gaia (Refound open and
    globular clusters and some features)
    3.Fe-Dynamical Tagging with LAMOST-Gaia (locally)
    4. Did not have time to apply the SNN
    algorithm to Gaia DR2 beyond Orion.
    To be continued…….

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  45. Ken Van Tilburg (NYU & IAS)
    => A DM subhalo/blob heavier than 2 * 10^7 solar masses with a scale radius of 0.4 pc and line-of-sight
    distance of 2 kpc would have shown up as an outlier larger than any measured test statistic
    Astrometric, weak, gravitational lensing
    by completely dark, compact, dark matter clumps
    in the LMC foreground

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  46. Sihao Cheng (JHU)
    RR Lyrae distraction with Sergey
    Got Help to calibrate RR Lyrae color
    First action distribution in my life
    Learnt useful knowledge of Gaia, lightcurve data, RR Lyrae property, dynamics
    Co m=4 m=2
    Assume Flat
    rotation curve
    Omega_p ~ 1.5
    R_co ~ 5.3 kpc
    Thanks to Wilma and Johanna
    JR
    Lz

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  47. L L (Princeton University)
    Velocity Ellipsoid of the Milky Way’s Stellar Halo

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  48. Andy Casey
    Monash University (Melbourne, Australia)
    ● I learned a tonne of stuff this week, and formed new
    collaborations.
    ● Inferring binarity for ~10 million stars in Gaia: detection,
    characterisation (period, semi-amplitude, inclination).
    ● Built a non-parametric model of binarity across the
    H-R diagram using astrometry, radial velocity
    (absence/scatter), colours, systematics, photometric
    variability, etc. (~210 million parameters)
    ● Found a few candidate stellar-mass black hole binary
    systems.
    ● Used Gaia data to kill off multi-modality in APOGEE
    binary solutions.
    ● Made a Python tool to query Gaia forecast tool.
    Through collaboration and discussions with Badenes,
    El-Badry, Foreman-Mackey, Hogg, Holl, Michalik,
    Hernandez, Koposov, and Price-Whelan.
    Slide design by Adrian Price-Whelan

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  49. Natalie Hinkel (Vanderbilt -> Southwest Research Institute)
    I did: Some awesome visualizations with
    AMNH and Jonathan Gagné, Jackie
    Faherty, & Keith Hawkins. Young moving
    groups -- hint of a chemical stream?
    Still working on: HYPOGEE...111 stars
    I also am using (tried? still trying?):
    Elements = [-0.25, 0, 0.25] Fe, C, O, Ti, Mg, Na, Al
    [Eu/Fe] in GALAH+APOGEE: -0.14 (0.15 dex)
    [Eu/Fe] in Gaia-ESO+APOGEE: 0.02 (0.18 dex)

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  50. We found 4 new coeval groups !
    ● Distances 70 ‒ 180 pc
    ● Ages 100 ‒ 400 Myr
    Jonathan Gagné (Carnegie DTM)

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  51. Joris De Ridder KU Leuven - DPAC CU7
    Ceci n'est pas un 'spectrum'
    Order
    OPTICS clustering
    35K RRab
    4h download time
    50K RRL
    SMC
    Sgr stream
    Bump
    NGC 6229
    Sgr dSph
    M3
    M72
    IC 4499
    M53

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  52. Mercè Romero-Gómez
    (Institute of Cosmos Sciences, University of Barcelona - ICCUB, DPAC-CU9)
    ● I used J. Gagné’s selection of
    YLAs to re-compute dynamical
    ages via traceback analysis
    (backward orbital integration).
    ● For most of the YLAs we are
    able to provide an estimated age
    or a range, improving
    GDR1-TGAS results.
    ● For TW-Hya, we now have 22
    members and give an age
    estimate of 4-11Myr.
    TW - Hya, estimated age from literature: 3-15Myr
    Not available using GDR1-TGAS
    __ observed
    __ estimated
    ... errors

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  53. -
    Click to add text
    Slide design by Andy Casey

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  54. I was searching for
    this “blob” in Gaia
    DR2 to check if it’s
    associated with Pal
    5’s leading arm
    My project on Pal 5:
    Sarah Pearson (Columbia University)
    As predicted by my
    simulations of Pal 5 in a
    barred Galactic
    potential
    CMD of red blob region CMD of Pal 5 and blob
    CMD of Pal 5 (shifted) to closer
    distance and the blob
    Pal 5 in DR2:

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  55. Christina Eilers (MPIA)
    ● linear model to obtain spectroscopic
    parallaxes from APOGEE spectra + 3 colors
    ● distances to ~50,000 RGB stars out to ~30 kpc
    with < 10% uncertainties
    In collaboration with David W Hogg, Melissa
    Ness, Hans-Walter Rix, Daniel Michalik & Sven
    Buder! Thank you!!

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  56. Daniel Hestroffer (Paris obs. +DPAC)
    ● I did this:
    ○ New connections! (Dank U Santiago and the Leiden
    Sterrewacht group ;) & Co.
    ○ Discussions on stellar perturbations on Solar System, and brown dwarfs
    ○ Start astrometric reductions from stellar catalogue
    ● I didn’t yet do that
    ○ Looking forward to DR3 and next GaiaSprint (this was my 1st one)
    & more Solar System Science? (SSO rocks!)
    Thanks to NYC GaiaSprint organizers and Flatiron inst.
    [email protected]

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  57. I did/learned that:
    ● finding stars in MC stream is truly amazing (thanks Elena D'Onghia)
    though very difficult (thanks (?) Vasily Belokurov)
    ○ Found that one suggested leading stream star is in the disk (hence discarded)
    ● people seem extremely interested using the variable star samples (especially RR Lyrae)
    ○ Our partially disjoint classifier and detailed analyses tables successfully confused people,
    so we provided above link to get unconfused)
    ○ Many people hack first / read later (is reading papers overrated?)
    ● That it was very useful&pleasing to contribute in people’s understanding of the data
    ● This sprint was the best scientific experience I had (so far ;)

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  58. I did/learned that:
    ● finding stars in MC stream is truly amazing (thanks Elena D'Onghia)
    though very difficult (thanks (?) Vasily Belokurov)
    ○ Found that one suggested leading stream star is in the disk (hence discarded)
    ● people seem extremely interested using the variable star samples (especially RR Lyrae)
    ○ Our partially disjoint classifier and detailed analyses tables successfully confused people,
    so we provided above link to get unconfused.
    ○ Many people hack first / read later (is reading papers overrated?)
    ● That it was very useful & pleasing to contribute in people’s understanding of the data
    ● This sprint was the best scientific experience I ever had!
    ● Flatiron Institute: many thanks for the travel support, great facilities and super tasty food

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  59. Axel Widmark
    Unresolved multiple stellar systems
    White dwarfs population statistics
    Unresolved
    WD binaries
    Some WD binaries are
    not found when looking
    at a 2D at a parameter
    space.
    Complications:
    inaccuracies in WD color
    models (data-driven
    corrections with Boris
    Leistedt)

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  60. Eleonora Zari
    Leiden Observatory
    ● I made a 3D density map of PMS stars
    within d = 500 pc
    ● I studied the kinematics of the stars within
    the contours and rediscovered the Sun
    motion!

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  61. ● I consulted with various
    people about the
    morphology of the group.
    ● I found that 14 of these
    stars are bright X-ray
    sources.
    ● I learned that one can
    measure acceleration and
    constrain orbit with
    Hipparcos+Gaia astrometry.
    Semyeong Oh (Princeton)

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  62. Ana Bonaca (Harvard)
    Members of the Jhelum stream (proper motion-selected along the main sequence):
    Possible origins: ● Caustic shell
    ● Two progenitors
    ● Precession of the orbital plane
    ● Chaos!

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  63. Went looking for structure in
    the outer disk.
    Stepping PM in Galactic
    longitude coord; mostly
    showing “normal” disk
    behavior + Mon + ACS + EBS
    + Etc. No big surprises(?)
    Lots of thanks to Chervin
    Laporte for the ideas and for
    doing a more proper job
    Colin Slater (University of Washington)
    MSTO stars, 20.5 > G > 19, low parallax

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  64. Boris Leistedt (NYU)
    Hierarchical inference of velocity distribution
    Application to halo stars: improved parallaxes
    with PMs marginalized (+5/10 points in SNR!)
    Weak dust constraints from HRD only

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  65. Sven Buder (MPIA)
    Gaia/GALAH@Hayden planetarium
    Thanks:
    - For using GALAH DR2
    - To Gaia and DPAC
    - To Flatiron
    [Ba/Fe] as age indicator

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  66. Borja Anguiano (University of Virginia)




    single point = 1000 stars
    Z -
    vz
    Ratio between semi-axes of the velocity ellipsoid

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  67. Gracias Ele :D!

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  68. Jacob Hamer (Johns Hopkins University)
    ● Went from 140 Hot Jupiters to ~340 for which I
    could calculate UVW velocities (!)
    ● Learned many things that made it all that easier
    (thanks Adrian and others!)
    ● Future:
    ○ Disentangle metallicity-age effect
    ○ Select a better control sample to do that
    ○ Extinction correction
    ○ Better MS selection

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  69. Constrain vertical disk heating
    Jz(age,R) = Jz,birth + Jz,heating
    Data-driven deep learning
    photometric stellar parameters

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  70. Elena D’Onghia (UW-Madison)
    The MW in Action space
    Simulation of Milky Way galaxy with a
    buckling bar of 5 kpc. Stars selected within 1
    kpc from the Sun.
    At the time of the buckling of the bar
    there is an empty region in JR- Lz
    (thanks Wilma)
    Test to look for corotation in Action Space: we can look at Perseus, Outer Arm
    Vr
    Vphi
    See Chao Liu’s plots
    eccentricity

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  71. Carles Badenes (University of Pittsburgh)
    ● Talked to LOTS of people, learned
    A TON. Special thanks to Andy
    Casey, Adrian Price-Whelan,
    Kareem El-Badry, and Josh Peek!
    ● Stellar multiplicity with Gaia RV
    dispersions: doable but needs
    more work. Andy Casey’s
    approach is more powerful (but
    potentially harder to interpret).
    ● Many cool systems (bunnies) in
    the censored zone!

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  72. Megan Bedell (Flatiron)
    Things I did:
    ● Many ADQL queries
    ● Looked at kinematics + stellar age +
    composition connections with solar
    twins
    ● Found co-moving Gaia sources in the
    Kepler field
    ● Fun science with excellent people!
    One cool result:
    (with Ben Montet (UChicago))
    This star is 4
    Gyr old (from
    isochrones +
    Gaia plx)
    These stars
    are comoving
    in Gaia DR2!
    This star has a Hot
    Jupiter and a
    4-day rotation period
    (from Kepler PSF
    modeling)

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  73. View Slide

  74. Jose Hernandez (ESAC)
    I did this: Learned a lot, got a few odd sources which I’d like to investigate, explained the
    astrometry flags, good some ideas of what could be helpful to try improving, enjoyed seeing how
    Gaia data gets used in very imaginative and surprising ways.
    Got many new ideas of things to look at… so may be DR3 will get delayed a bit :-)
    I did that: Worked with Jackie, Tim, Daniel and Alcione on possible binaries found comparing
    DR1/DR2 proper motions, investigated DR2 pm systematics in the RF.

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  75. Ted Mackereth (Liverpool John Moores University, UK)
    - I DIDNT do my proposed
    project!
    - I learned stuff about actions
    and angles (thanks to Wilma
    Trick: Action Woman), learned
    stuff about the bar (and some
    bars) from Jason - and made a
    .gif, because thats what we do
    now, right? (thanks Adrian)
    - Once again, had a great week
    with all you great folks.

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  76. View Slide

  77. Rocio Kiman
    (The Graduate Center, CUNY)
    Want I did
    ● Defined color cuts for M dwarfs in G-RP and BP-G.
    ● With some cut to keep good photometry, G-RP is a proxy for spt.
    ● Added cut in absolute magnitude to remove giants contamination.

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  78. Denis Erkal (University of Surrey)
    Did: Had fun, learned a lot, struggled with streams near GCs. -> Sagittarius
    Sgr on sky
    Sgr PM
    Traced bifurcation closer in
    3d Sgr in RR Lyrae
    Across stream direction

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  79. Mark Fardal (STScI)
    Did: messed with Sagittarius RR Lyraes and
    measured their tangential motion. Looked at lots of
    awesome Sag plots by Denis and Vasily.
    Failed: detecting fainter streams in proper motion
    space. But at least now I’ve learned how to do it.
    And learned a lot from
    many awesome people!

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  80. Melissa Ness (Flatiron) (Columbia)

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  81. Kathryn V Johnston (Columbia University)
    I did this:
    ● Provided (?helpful?) thoughts for projects with Sarah Pearson, David Hendel,
    Chervin Laporte; Ana Bonaca
    ● Appreciated being surrounded by exciting science;
    ● Interrupted Wilma too many times as she imparted great action-intuition;
    THANKS:
    ● Gaia team
    ● Sprint leaders - Hogg! Ana! Adrian! …..
    ● Jackie for AMNH immersion
    ● And fellow sprinters/ramblers…...

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  82. Cecilia Mateu ● Remember to use the filter astro_excess_noise<2
    ● Distances to ALL SOS RRLyrae computed with
    PMG from R. Beaton @ Gaia Sprint (available
    online)
    ● In progress: testing RRL catalogue from Classifier
    Table (Berry Holl) -> 195,780 (RR*) matched to
    compilation of (~12) RRLyrae surveys from
    literature
    -> advantage: sky uniformity, at cost of
    higher contamination
    SOS RR (~120K, astro_excess_noise<2)
    with (lots of) help from Berry Holl and Joris de Ridder

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  83. Ting Li (Fermilab)
    Follow-up on stellar streams:
    ● ATLAS
    ● Pal 5
    ● Jhelum
    Pal 5
    ATLAS Stream

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