An improved mass determination for M31 from its satellite galaxies

Patrick Côté, Mario Mateo, W. L W Sargent, Edward W Olszewski

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The High-Resolution Echelle Spectrometer on the Keck I telescope has been used to measure the first radial velocities for stars belonging to the Andromeda I and III dwarf spheroidal galaxies. Our radial velocity for And III matches that reported by Blitz & Robishaw for an adjacent H I gas complex, supporting the association of this galaxy with a high-velocity cloud. New and previously published radial velocities for a sample of confirmed or suspected M31 satellites are combined with a homogeneous set of distance estimates to calculate the total mass of M31. Assuming the satellite orbits are isotropic, we find a median mass of MA ≃ (7.9 ± 0.5) × 1011 M from eight candidate satellites having deprojected distances from M31 in excess of RA ≃ 100 kpc. If the orbits are radial, the inferred mass increases to MA ≃ (21.5 ± 3.8) × 1011 M for circular orbits, the enclosed mass is MA ≃ (3.7 ± 0.4) × 1011 M. These masses are somewhat lower than those found for luminous spiral galaxies based on the ensemble dynamics of the their satellites, although the estimates are nevertheless consistent given the large uncertainties.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume537
Issue number2 PART 2
StatePublished - Jul 10 2000

Fingerprint

galaxies
radial velocity
Andromeda
satellite orbits
circular orbits
dwarf galaxies
spiral galaxies
estimates
spectrometer
telescopes
spectrometers
orbits
stars
high resolution
gases
gas

Keywords

  • Galaxies: halos
  • Galaxies: individual (M31)
  • Galaxies: kinematics and dynamics
  • Galaxies: spiral
  • Intergalactic medium

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

An improved mass determination for M31 from its satellite galaxies. / Côté, Patrick; Mateo, Mario; Sargent, W. L W; Olszewski, Edward W.

In: Astrophysical Journal, Vol. 537, No. 2 PART 2, 10.07.2000.

Research output: Contribution to journalArticle

Côté, P, Mateo, M, Sargent, WLW & Olszewski, EW 2000, 'An improved mass determination for M31 from its satellite galaxies', Astrophysical Journal, vol. 537, no. 2 PART 2.
Côté, Patrick ; Mateo, Mario ; Sargent, W. L W ; Olszewski, Edward W. / An improved mass determination for M31 from its satellite galaxies. In: Astrophysical Journal. 2000 ; Vol. 537, No. 2 PART 2.
@article{3df426e1beaf494db37e8bd7c61c5373,
title = "An improved mass determination for M31 from its satellite galaxies",
abstract = "The High-Resolution Echelle Spectrometer on the Keck I telescope has been used to measure the first radial velocities for stars belonging to the Andromeda I and III dwarf spheroidal galaxies. Our radial velocity for And III matches that reported by Blitz & Robishaw for an adjacent H I gas complex, supporting the association of this galaxy with a high-velocity cloud. New and previously published radial velocities for a sample of confirmed or suspected M31 satellites are combined with a homogeneous set of distance estimates to calculate the total mass of M31. Assuming the satellite orbits are isotropic, we find a median mass of MA ≃ (7.9 ± 0.5) × 1011 M⊙ from eight candidate satellites having deprojected distances from M31 in excess of RA ≃ 100 kpc. If the orbits are radial, the inferred mass increases to MA ≃ (21.5 ± 3.8) × 1011 M⊙ for circular orbits, the enclosed mass is MA ≃ (3.7 ± 0.4) × 1011 M⊙. These masses are somewhat lower than those found for luminous spiral galaxies based on the ensemble dynamics of the their satellites, although the estimates are nevertheless consistent given the large uncertainties.",
keywords = "Galaxies: halos, Galaxies: individual (M31), Galaxies: kinematics and dynamics, Galaxies: spiral, Intergalactic medium",
author = "Patrick C{\^o}t{\'e} and Mario Mateo and Sargent, {W. L W} and Olszewski, {Edward W}",
year = "2000",
month = "7",
day = "10",
language = "English (US)",
volume = "537",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2 PART 2",

}

TY - JOUR

T1 - An improved mass determination for M31 from its satellite galaxies

AU - Côté, Patrick

AU - Mateo, Mario

AU - Sargent, W. L W

AU - Olszewski, Edward W

PY - 2000/7/10

Y1 - 2000/7/10

N2 - The High-Resolution Echelle Spectrometer on the Keck I telescope has been used to measure the first radial velocities for stars belonging to the Andromeda I and III dwarf spheroidal galaxies. Our radial velocity for And III matches that reported by Blitz & Robishaw for an adjacent H I gas complex, supporting the association of this galaxy with a high-velocity cloud. New and previously published radial velocities for a sample of confirmed or suspected M31 satellites are combined with a homogeneous set of distance estimates to calculate the total mass of M31. Assuming the satellite orbits are isotropic, we find a median mass of MA ≃ (7.9 ± 0.5) × 1011 M⊙ from eight candidate satellites having deprojected distances from M31 in excess of RA ≃ 100 kpc. If the orbits are radial, the inferred mass increases to MA ≃ (21.5 ± 3.8) × 1011 M⊙ for circular orbits, the enclosed mass is MA ≃ (3.7 ± 0.4) × 1011 M⊙. These masses are somewhat lower than those found for luminous spiral galaxies based on the ensemble dynamics of the their satellites, although the estimates are nevertheless consistent given the large uncertainties.

AB - The High-Resolution Echelle Spectrometer on the Keck I telescope has been used to measure the first radial velocities for stars belonging to the Andromeda I and III dwarf spheroidal galaxies. Our radial velocity for And III matches that reported by Blitz & Robishaw for an adjacent H I gas complex, supporting the association of this galaxy with a high-velocity cloud. New and previously published radial velocities for a sample of confirmed or suspected M31 satellites are combined with a homogeneous set of distance estimates to calculate the total mass of M31. Assuming the satellite orbits are isotropic, we find a median mass of MA ≃ (7.9 ± 0.5) × 1011 M⊙ from eight candidate satellites having deprojected distances from M31 in excess of RA ≃ 100 kpc. If the orbits are radial, the inferred mass increases to MA ≃ (21.5 ± 3.8) × 1011 M⊙ for circular orbits, the enclosed mass is MA ≃ (3.7 ± 0.4) × 1011 M⊙. These masses are somewhat lower than those found for luminous spiral galaxies based on the ensemble dynamics of the their satellites, although the estimates are nevertheless consistent given the large uncertainties.

KW - Galaxies: halos

KW - Galaxies: individual (M31)

KW - Galaxies: kinematics and dynamics

KW - Galaxies: spiral

KW - Intergalactic medium

UR - http://www.scopus.com/inward/record.url?scp=0034631543&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034631543&partnerID=8YFLogxK

M3 - Article

VL - 537

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2 PART 2

ER -