The GALAH survey: Stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere, and metallicity

Alice C. Quillen, Gayandhi De Silva, Sanjib Sharma, Michael Hayden, Ken Freeman, Joss Bland-Hawthorn, Maruša Zerjal, Martin Asplund, Sven Buder, Valentina D'Orazi, Ly Duong, Janez Kos, Jane Lin, Karin Lind, Sarah Martell, Katharine Schlesinger, Jeffrey D. Simpson, Daniel B. Zucker, Tomaz Zwitter, Borja Anguiano & 13 others Daniela Carollo, Luca Casagrande, Klemen Cotar, Peter L. Cottrell, Michael Ireland, Prajwal R. Kafle, Jonathan Horner, Geraint F. Lewis, David M. Nataf, Yuan Sen Ting, Fred Watson, Rob Wittenmyer, Rosemary Wyse

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Using GALAH (GALactic Archaeology with HERMES) survey data of nearby stars, we look at how structure in the planar (u, v) velocity distribution depends on metallicity and on viewing direction within the Galaxy. In nearby stars with distance d ≲ 1 kpc, the Hercules stream is most strongly seen in higher metallicity stars [Fe/H] > 0.2. The Hercules stream peak v value depends on viewed galactic longitude, which we interpret as due to the gap between the stellar stream and more circular orbits being associated with a specific angular momentum value of about 1640 km s-1 kpc. The association of the gap with a particular angular momentum value supports a bar resonant model for the Hercules stream. Moving groups previously identified in Hipparcos (HIgh Precision Parallax COllecting Satellite) observations are easiest to see in stars nearer than 250 pc, and their visibility and peak velocities in the velocity distributions depends on both viewing direction (galactic longitude and hemisphere) and metallicity. We infer that there is fine structure in local velocity distributions that varies over distances of a few hundred pc in the Galaxy.

Original languageEnglish
Pages (from-to)228-254
Number of pages27
JournalMonthly Notices of the Royal Astronomical Society
Volume478
Issue number1
DOIs
Publication statusPublished - 21 Jul 2018

Fingerprint

archaeology
longitude
hemispheres
metallicity
velocity distribution
stars
angular momentum
galaxies
parallax
satellite observation
circular orbits
visibility
fine structure
distribution

Cite this

Quillen, Alice C. ; De Silva, Gayandhi ; Sharma, Sanjib ; Hayden, Michael ; Freeman, Ken ; Bland-Hawthorn, Joss ; Zerjal, Maruša ; Asplund, Martin ; Buder, Sven ; D'Orazi, Valentina ; Duong, Ly ; Kos, Janez ; Lin, Jane ; Lind, Karin ; Martell, Sarah ; Schlesinger, Katharine ; Simpson, Jeffrey D. ; Zucker, Daniel B. ; Zwitter, Tomaz ; Anguiano, Borja ; Carollo, Daniela ; Casagrande, Luca ; Cotar, Klemen ; Cottrell, Peter L. ; Ireland, Michael ; Kafle, Prajwal R. ; Horner, Jonathan ; Lewis, Geraint F. ; Nataf, David M. ; Ting, Yuan Sen ; Watson, Fred ; Wittenmyer, Rob ; Wyse, Rosemary. / The GALAH survey : Stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere, and metallicity. In: Monthly Notices of the Royal Astronomical Society. 2018 ; Vol. 478, No. 1. pp. 228-254.
@article{8b38b35d671e4d1e98dc723e86dfbc65,
title = "The GALAH survey: Stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere, and metallicity",
abstract = "Using GALAH (GALactic Archaeology with HERMES) survey data of nearby stars, we look at how structure in the planar (u, v) velocity distribution depends on metallicity and on viewing direction within the Galaxy. In nearby stars with distance d ≲ 1 kpc, the Hercules stream is most strongly seen in higher metallicity stars [Fe/H] > 0.2. The Hercules stream peak v value depends on viewed galactic longitude, which we interpret as due to the gap between the stellar stream and more circular orbits being associated with a specific angular momentum value of about 1640 km s-1 kpc. The association of the gap with a particular angular momentum value supports a bar resonant model for the Hercules stream. Moving groups previously identified in Hipparcos (HIgh Precision Parallax COllecting Satellite) observations are easiest to see in stars nearer than 250 pc, and their visibility and peak velocities in the velocity distributions depends on both viewing direction (galactic longitude and hemisphere) and metallicity. We infer that there is fine structure in local velocity distributions that varies over distances of a few hundred pc in the Galaxy.",
keywords = "Galaxy: Disc, Galaxy: Evolution, Galaxy: Kinematics and dynamics",
author = "Quillen, {Alice C.} and {De Silva}, Gayandhi and Sanjib Sharma and Michael Hayden and Ken Freeman and Joss Bland-Hawthorn and Maruša Zerjal and Martin Asplund and Sven Buder and Valentina D'Orazi and Ly Duong and Janez Kos and Jane Lin and Karin Lind and Sarah Martell and Katharine Schlesinger and Simpson, {Jeffrey D.} and Zucker, {Daniel B.} and Tomaz Zwitter and Borja Anguiano and Daniela Carollo and Luca Casagrande and Klemen Cotar and Cottrell, {Peter L.} and Michael Ireland and Kafle, {Prajwal R.} and Jonathan Horner and Lewis, {Geraint F.} and Nataf, {David M.} and Ting, {Yuan Sen} and Fred Watson and Rob Wittenmyer and Rosemary Wyse",
year = "2018",
month = "7",
day = "21",
doi = "10.1093/mnras/sty865",
language = "English",
volume = "478",
pages = "228--254",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "OXFORD UNIV PRESS UNITED KINGDOM",
number = "1",

}

Quillen, AC, De Silva, G, Sharma, S, Hayden, M, Freeman, K, Bland-Hawthorn, J, Zerjal, M, Asplund, M, Buder, S, D'Orazi, V, Duong, L, Kos, J, Lin, J, Lind, K, Martell, S, Schlesinger, K, Simpson, JD, Zucker, DB, Zwitter, T, Anguiano, B, Carollo, D, Casagrande, L, Cotar, K, Cottrell, PL, Ireland, M, Kafle, PR, Horner, J, Lewis, GF, Nataf, DM, Ting, YS, Watson, F, Wittenmyer, R & Wyse, R 2018, 'The GALAH survey: Stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere, and metallicity' Monthly Notices of the Royal Astronomical Society, vol. 478, no. 1, pp. 228-254. https://doi.org/10.1093/mnras/sty865

The GALAH survey : Stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere, and metallicity. / Quillen, Alice C.; De Silva, Gayandhi; Sharma, Sanjib; Hayden, Michael; Freeman, Ken; Bland-Hawthorn, Joss; Zerjal, Maruša; Asplund, Martin; Buder, Sven; D'Orazi, Valentina; Duong, Ly; Kos, Janez; Lin, Jane; Lind, Karin; Martell, Sarah; Schlesinger, Katharine; Simpson, Jeffrey D.; Zucker, Daniel B.; Zwitter, Tomaz; Anguiano, Borja; Carollo, Daniela; Casagrande, Luca; Cotar, Klemen; Cottrell, Peter L.; Ireland, Michael; Kafle, Prajwal R.; Horner, Jonathan; Lewis, Geraint F.; Nataf, David M.; Ting, Yuan Sen; Watson, Fred; Wittenmyer, Rob; Wyse, Rosemary.

In: Monthly Notices of the Royal Astronomical Society, Vol. 478, No. 1, 21.07.2018, p. 228-254.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The GALAH survey

T2 - Stellar streams and how stellar velocity distributions vary with Galactic longitude, hemisphere, and metallicity

AU - Quillen, Alice C.

AU - De Silva, Gayandhi

AU - Sharma, Sanjib

AU - Hayden, Michael

AU - Freeman, Ken

AU - Bland-Hawthorn, Joss

AU - Zerjal, Maruša

AU - Asplund, Martin

AU - Buder, Sven

AU - D'Orazi, Valentina

AU - Duong, Ly

AU - Kos, Janez

AU - Lin, Jane

AU - Lind, Karin

AU - Martell, Sarah

AU - Schlesinger, Katharine

AU - Simpson, Jeffrey D.

AU - Zucker, Daniel B.

AU - Zwitter, Tomaz

AU - Anguiano, Borja

AU - Carollo, Daniela

AU - Casagrande, Luca

AU - Cotar, Klemen

AU - Cottrell, Peter L.

AU - Ireland, Michael

AU - Kafle, Prajwal R.

AU - Horner, Jonathan

AU - Lewis, Geraint F.

AU - Nataf, David M.

AU - Ting, Yuan Sen

AU - Watson, Fred

AU - Wittenmyer, Rob

AU - Wyse, Rosemary

PY - 2018/7/21

Y1 - 2018/7/21

N2 - Using GALAH (GALactic Archaeology with HERMES) survey data of nearby stars, we look at how structure in the planar (u, v) velocity distribution depends on metallicity and on viewing direction within the Galaxy. In nearby stars with distance d ≲ 1 kpc, the Hercules stream is most strongly seen in higher metallicity stars [Fe/H] > 0.2. The Hercules stream peak v value depends on viewed galactic longitude, which we interpret as due to the gap between the stellar stream and more circular orbits being associated with a specific angular momentum value of about 1640 km s-1 kpc. The association of the gap with a particular angular momentum value supports a bar resonant model for the Hercules stream. Moving groups previously identified in Hipparcos (HIgh Precision Parallax COllecting Satellite) observations are easiest to see in stars nearer than 250 pc, and their visibility and peak velocities in the velocity distributions depends on both viewing direction (galactic longitude and hemisphere) and metallicity. We infer that there is fine structure in local velocity distributions that varies over distances of a few hundred pc in the Galaxy.

AB - Using GALAH (GALactic Archaeology with HERMES) survey data of nearby stars, we look at how structure in the planar (u, v) velocity distribution depends on metallicity and on viewing direction within the Galaxy. In nearby stars with distance d ≲ 1 kpc, the Hercules stream is most strongly seen in higher metallicity stars [Fe/H] > 0.2. The Hercules stream peak v value depends on viewed galactic longitude, which we interpret as due to the gap between the stellar stream and more circular orbits being associated with a specific angular momentum value of about 1640 km s-1 kpc. The association of the gap with a particular angular momentum value supports a bar resonant model for the Hercules stream. Moving groups previously identified in Hipparcos (HIgh Precision Parallax COllecting Satellite) observations are easiest to see in stars nearer than 250 pc, and their visibility and peak velocities in the velocity distributions depends on both viewing direction (galactic longitude and hemisphere) and metallicity. We infer that there is fine structure in local velocity distributions that varies over distances of a few hundred pc in the Galaxy.

KW - Galaxy: Disc

KW - Galaxy: Evolution

KW - Galaxy: Kinematics and dynamics

UR - http://www.scopus.com/inward/record.url?scp=85048500215&partnerID=8YFLogxK

U2 - 10.1093/mnras/sty865

DO - 10.1093/mnras/sty865

M3 - Article

VL - 478

SP - 228

EP - 254

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 1

ER -