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 Žerjal; 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; 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

doi:10.1093/mnras/sty865

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 Žerjal, 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 AnguianoDaniela 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

^*Corresponding author for this work

Centre in Astronomy, Astrophysics & Astrophotonics

Research output: Contribution to journal › Article › peer-review

26 Citations (Scopus)

38 Downloads (Pure)

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 language	English
Pages (from-to)	228-254
Number of pages	27
Journal	Monthly Notices of the Royal Astronomical Society
Volume	478
Issue number	1
DOIs	https://doi.org/10.1093/mnras/sty865
Publication status	Published - 21 Jul 2018

Bibliographical note

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society, Volume 478, Issue 1, 21 July 2018, Pages 228–254, https://doi.org/10.1093/mnras/sty865. Copyright 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

Keywords

Galaxy: disc
Galaxy: evolution
Galaxy: kinematics and dynamics
Galaxy: Kinematics and dynamics
Galaxy: Disc
Galaxy: Evolution

Access to Document

10.1093/mnras/sty865

Publisher version (open access)Final published version, 15.1 MBLicence: Other

Cite this

Quillen, A. C., De Silva, G., Sharma, S., Hayden, M., Freeman, K., Bland-Hawthorn, J., Žerjal, M., Asplund, M., Buder, S., D'Orazi, V., Duong, L., Kos, J., Lin, J., Lind, K., Martell, S., Schlesinger, K., Simpson, J. D., Zucker, D. B., Zwitter, T., ... 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, 478(1), 228-254. https://doi.org/10.1093/mnras/sty865

@article{f444da50cff3483d9fe1f03efe97ec5d,

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, Galaxy: Kinematics and dynamics, Galaxy: Disc, Galaxy: Evolution",

author = "Quillen, {Alice C.} and {De Silva}, Gayandhi and Sanjib Sharma and Michael Hayden and Ken Freeman and Joss Bland-Hawthorn and Maru{\v s}a {\v Z}erjal 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",

note = "This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society, Volume 478, Issue 1, 21 July 2018, Pages 228–254, https://doi.org/10.1093/mnras/sty865. Copyright 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.",

year = "2018",

month = jul,

day = "21",

doi = "10.1093/mnras/sty865",

language = "English",

volume = "478",

pages = "228--254",

journal = "Monthly Notices of the Royal Astronomical Society: Letters",

issn = "1745-3925",

publisher = "Oxford University Press",

number = "1",

}

Quillen, AC, De Silva, G, Sharma, S, Hayden, M, Freeman, K, Bland-Hawthorn, J, Žerjal, 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

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 - Žerjal, 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

N1 - This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society, Volume 478, Issue 1, 21 July 2018, Pages 228–254, https://doi.org/10.1093/mnras/sty865. Copyright 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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

KW - Galaxy: Kinematics and dynamics

KW - Galaxy: Disc

KW - Galaxy: Evolution

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: Letters

JF - Monthly Notices of the Royal Astronomical Society: Letters

SN - 1745-3925

IS - 1

ER -

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

Abstract

Bibliographical note

Keywords

Access to Document

Other files and links

Fingerprint

Cite this