The effect of galactic tides on the apparent mass-to-light ratios in dwarf spheroidal galaxies

Slawomir Piatek, Carlton Pryor

Research output: Contribution to journalArticle

111 Citations (Scopus)

Abstract

We have performed numerical simulations to investigate whether galactic tides can elevate the apparent mass-to-light ratio (script M sign/L) in a dwarf spheroidal galaxy (dSph). In our simulations the dSph is composed only of luminous matter and falls towards the Milky Way on various orbits and in various galactic potentials starting from apogalacticon. We assume a single perigalacticon passage in which the close encounter with the Milky Way produces strong tides that greatly affect the structure and the kinematics of the dSph. We find that even when tides affect the structure and the kinematics of the dSph, they fail to inflate the central script M sign/L. Tides produce large ordered motions rather than large random motions; a clear signature of these motions is apparent rotation. Tides can inflate the global script M sign/L to a value as large as ∼40; however, this is solely due to the ordered motions. Comparing our results with real dSphs, we conclude that galactic tides at the most recent pericenter passage have not inflated the apparent script M sign/L's.

Original languageEnglish (US)
Pages (from-to)1071-1085
Number of pages15
JournalAstronomical Journal
Volume109
Issue number3
DOIs
StatePublished - Mar 1995

Fingerprint

mass to light ratios
dwarf galaxies
tides
tide
kinematics
encounters
simulation
effect
signatures
orbits

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

@article{3b077701d9dd46a888e80771d0bf7fd9,
title = "The effect of galactic tides on the apparent mass-to-light ratios in dwarf spheroidal galaxies",
abstract = "We have performed numerical simulations to investigate whether galactic tides can elevate the apparent mass-to-light ratio (script M sign/L) in a dwarf spheroidal galaxy (dSph). In our simulations the dSph is composed only of luminous matter and falls towards the Milky Way on various orbits and in various galactic potentials starting from apogalacticon. We assume a single perigalacticon passage in which the close encounter with the Milky Way produces strong tides that greatly affect the structure and the kinematics of the dSph. We find that even when tides affect the structure and the kinematics of the dSph, they fail to inflate the central script M sign/L. Tides produce large ordered motions rather than large random motions; a clear signature of these motions is apparent rotation. Tides can inflate the global script M sign/L to a value as large as ∼40; however, this is solely due to the ordered motions. Comparing our results with real dSphs, we conclude that galactic tides at the most recent pericenter passage have not inflated the apparent script M sign/L's.",
author = "Slawomir Piatek and Carlton Pryor",
year = "1995",
month = "3",
doi = "10.1086/117342",
language = "English (US)",
volume = "109",
pages = "1071--1085",
journal = "Astronomical Journal",
issn = "0004-6256",
publisher = "IOP Publishing Ltd.",
number = "3",

}

The effect of galactic tides on the apparent mass-to-light ratios in dwarf spheroidal galaxies. / Piatek, Slawomir; Pryor, Carlton.

In: Astronomical Journal, Vol. 109, No. 3, 03.1995, p. 1071-1085.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The effect of galactic tides on the apparent mass-to-light ratios in dwarf spheroidal galaxies

AU - Piatek, Slawomir

AU - Pryor, Carlton

PY - 1995/3

Y1 - 1995/3

N2 - We have performed numerical simulations to investigate whether galactic tides can elevate the apparent mass-to-light ratio (script M sign/L) in a dwarf spheroidal galaxy (dSph). In our simulations the dSph is composed only of luminous matter and falls towards the Milky Way on various orbits and in various galactic potentials starting from apogalacticon. We assume a single perigalacticon passage in which the close encounter with the Milky Way produces strong tides that greatly affect the structure and the kinematics of the dSph. We find that even when tides affect the structure and the kinematics of the dSph, they fail to inflate the central script M sign/L. Tides produce large ordered motions rather than large random motions; a clear signature of these motions is apparent rotation. Tides can inflate the global script M sign/L to a value as large as ∼40; however, this is solely due to the ordered motions. Comparing our results with real dSphs, we conclude that galactic tides at the most recent pericenter passage have not inflated the apparent script M sign/L's.

AB - We have performed numerical simulations to investigate whether galactic tides can elevate the apparent mass-to-light ratio (script M sign/L) in a dwarf spheroidal galaxy (dSph). In our simulations the dSph is composed only of luminous matter and falls towards the Milky Way on various orbits and in various galactic potentials starting from apogalacticon. We assume a single perigalacticon passage in which the close encounter with the Milky Way produces strong tides that greatly affect the structure and the kinematics of the dSph. We find that even when tides affect the structure and the kinematics of the dSph, they fail to inflate the central script M sign/L. Tides produce large ordered motions rather than large random motions; a clear signature of these motions is apparent rotation. Tides can inflate the global script M sign/L to a value as large as ∼40; however, this is solely due to the ordered motions. Comparing our results with real dSphs, we conclude that galactic tides at the most recent pericenter passage have not inflated the apparent script M sign/L's.

UR - http://www.scopus.com/inward/record.url?scp=0001015511&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001015511&partnerID=8YFLogxK

U2 - 10.1086/117342

DO - 10.1086/117342

M3 - Article

AN - SCOPUS:0001015511

VL - 109

SP - 1071

EP - 1085

JO - Astronomical Journal

JF - Astronomical Journal

SN - 0004-6256

IS - 3

ER -