THE AZIMUTHAL DEPENDENCE of OUTFLOWS and ACCRETION DETECTED USING OVI ABSORPTION

Glenn G. Kacprzak, Sowgat Muzahid, Christopher W. Churchill, Nikole M. Nielsen, Jane Camilla Charlton

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

We report a bimodality in the azimuthal angle (Φ) distribution of gas around galaxies traced by O vi absorption. We present the mean Φ probability distribution function of 29 Hubble Space Telescope-imaged O vi absorbing (EW > 0.1) and 24 non-absorbing (EW < 0.1) isolated galaxies (0.08 0.67) within ∼200 kpc of background quasars. We show that equivalent width (EW) is anti-correlated with impact parameter and O vi covering fraction decreases from 80% within 50 kpc to 33% at 200 kpc. The presence of O vi absorption is azimuthally dependent and occurs between ± 10°-20° of the galaxy projected major axis and within ± 30° of the projected minor axis. We find higher EWs along the projected minor axis with weaker EWs along the project major axis. Highly inclined galaxies have the lowest covering fractions due to minimized outflow/inflow cross-section geometry. Absorbing galaxies also have bluer colors while non-absorbers have redder colors, suggesting that star formation is a key driver in the O vi detection rate. O vi surrounding blue galaxies exists primarily along the projected minor axis with wide opening angles while O vi surrounding red galaxies exists primarily along the projected major axis with smaller opening angles, which may explain why absorption around red galaxies is less frequently detected. Our results are consistent with a circumgalactic medium (CGM) originating from major axis-fed inflows/recycled gas and from minor axis-driven outflows. Non-detected O vi occurs between Φ = 20°-60°, suggesting that O vi is not mixed throughout the CGM and remains confined within the outflows and the disk-plane. We find low O vi covering fractions within of the projected major axis, suggesting that cool dense gas resides in a narrow planer geometry surrounded by diffuse O vi gas.

Original languageEnglish (US)
Article number22
JournalAstrophysical Journal
Volume815
Issue number1
DOIs
StatePublished - Dec 10 2015

Fingerprint

accretion
galaxies
outflow
gas
inflow
geometry
coverings
gases
cross section
color
probability distribution functions
Hubble Space Telescope
quasars
star formation
distribution
cross sections

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Kacprzak, Glenn G. ; Muzahid, Sowgat ; Churchill, Christopher W. ; Nielsen, Nikole M. ; Charlton, Jane Camilla. / THE AZIMUTHAL DEPENDENCE of OUTFLOWS and ACCRETION DETECTED USING OVI ABSORPTION. In: Astrophysical Journal. 2015 ; Vol. 815, No. 1.
@article{5fae4167643441ddb06e1b7b75f51a0a,
title = "THE AZIMUTHAL DEPENDENCE of OUTFLOWS and ACCRETION DETECTED USING OVI ABSORPTION",
abstract = "We report a bimodality in the azimuthal angle (Φ) distribution of gas around galaxies traced by O vi absorption. We present the mean Φ probability distribution function of 29 Hubble Space Telescope-imaged O vi absorbing (EW > 0.1) and 24 non-absorbing (EW < 0.1) isolated galaxies (0.08 0.67) within ∼200 kpc of background quasars. We show that equivalent width (EW) is anti-correlated with impact parameter and O vi covering fraction decreases from 80{\%} within 50 kpc to 33{\%} at 200 kpc. The presence of O vi absorption is azimuthally dependent and occurs between ± 10°-20° of the galaxy projected major axis and within ± 30° of the projected minor axis. We find higher EWs along the projected minor axis with weaker EWs along the project major axis. Highly inclined galaxies have the lowest covering fractions due to minimized outflow/inflow cross-section geometry. Absorbing galaxies also have bluer colors while non-absorbers have redder colors, suggesting that star formation is a key driver in the O vi detection rate. O vi surrounding blue galaxies exists primarily along the projected minor axis with wide opening angles while O vi surrounding red galaxies exists primarily along the projected major axis with smaller opening angles, which may explain why absorption around red galaxies is less frequently detected. Our results are consistent with a circumgalactic medium (CGM) originating from major axis-fed inflows/recycled gas and from minor axis-driven outflows. Non-detected O vi occurs between Φ = 20°-60°, suggesting that O vi is not mixed throughout the CGM and remains confined within the outflows and the disk-plane. We find low O vi covering fractions within of the projected major axis, suggesting that cool dense gas resides in a narrow planer geometry surrounded by diffuse O vi gas.",
author = "Kacprzak, {Glenn G.} and Sowgat Muzahid and Churchill, {Christopher W.} and Nielsen, {Nikole M.} and Charlton, {Jane Camilla}",
year = "2015",
month = "12",
day = "10",
doi = "10.1088/0004-637X/815/1/22",
language = "English (US)",
volume = "815",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

THE AZIMUTHAL DEPENDENCE of OUTFLOWS and ACCRETION DETECTED USING OVI ABSORPTION. / Kacprzak, Glenn G.; Muzahid, Sowgat; Churchill, Christopher W.; Nielsen, Nikole M.; Charlton, Jane Camilla.

In: Astrophysical Journal, Vol. 815, No. 1, 22, 10.12.2015.

Research output: Contribution to journalArticle

TY - JOUR

T1 - THE AZIMUTHAL DEPENDENCE of OUTFLOWS and ACCRETION DETECTED USING OVI ABSORPTION

AU - Kacprzak, Glenn G.

AU - Muzahid, Sowgat

AU - Churchill, Christopher W.

AU - Nielsen, Nikole M.

AU - Charlton, Jane Camilla

PY - 2015/12/10

Y1 - 2015/12/10

N2 - We report a bimodality in the azimuthal angle (Φ) distribution of gas around galaxies traced by O vi absorption. We present the mean Φ probability distribution function of 29 Hubble Space Telescope-imaged O vi absorbing (EW > 0.1) and 24 non-absorbing (EW < 0.1) isolated galaxies (0.08 0.67) within ∼200 kpc of background quasars. We show that equivalent width (EW) is anti-correlated with impact parameter and O vi covering fraction decreases from 80% within 50 kpc to 33% at 200 kpc. The presence of O vi absorption is azimuthally dependent and occurs between ± 10°-20° of the galaxy projected major axis and within ± 30° of the projected minor axis. We find higher EWs along the projected minor axis with weaker EWs along the project major axis. Highly inclined galaxies have the lowest covering fractions due to minimized outflow/inflow cross-section geometry. Absorbing galaxies also have bluer colors while non-absorbers have redder colors, suggesting that star formation is a key driver in the O vi detection rate. O vi surrounding blue galaxies exists primarily along the projected minor axis with wide opening angles while O vi surrounding red galaxies exists primarily along the projected major axis with smaller opening angles, which may explain why absorption around red galaxies is less frequently detected. Our results are consistent with a circumgalactic medium (CGM) originating from major axis-fed inflows/recycled gas and from minor axis-driven outflows. Non-detected O vi occurs between Φ = 20°-60°, suggesting that O vi is not mixed throughout the CGM and remains confined within the outflows and the disk-plane. We find low O vi covering fractions within of the projected major axis, suggesting that cool dense gas resides in a narrow planer geometry surrounded by diffuse O vi gas.

AB - We report a bimodality in the azimuthal angle (Φ) distribution of gas around galaxies traced by O vi absorption. We present the mean Φ probability distribution function of 29 Hubble Space Telescope-imaged O vi absorbing (EW > 0.1) and 24 non-absorbing (EW < 0.1) isolated galaxies (0.08 0.67) within ∼200 kpc of background quasars. We show that equivalent width (EW) is anti-correlated with impact parameter and O vi covering fraction decreases from 80% within 50 kpc to 33% at 200 kpc. The presence of O vi absorption is azimuthally dependent and occurs between ± 10°-20° of the galaxy projected major axis and within ± 30° of the projected minor axis. We find higher EWs along the projected minor axis with weaker EWs along the project major axis. Highly inclined galaxies have the lowest covering fractions due to minimized outflow/inflow cross-section geometry. Absorbing galaxies also have bluer colors while non-absorbers have redder colors, suggesting that star formation is a key driver in the O vi detection rate. O vi surrounding blue galaxies exists primarily along the projected minor axis with wide opening angles while O vi surrounding red galaxies exists primarily along the projected major axis with smaller opening angles, which may explain why absorption around red galaxies is less frequently detected. Our results are consistent with a circumgalactic medium (CGM) originating from major axis-fed inflows/recycled gas and from minor axis-driven outflows. Non-detected O vi occurs between Φ = 20°-60°, suggesting that O vi is not mixed throughout the CGM and remains confined within the outflows and the disk-plane. We find low O vi covering fractions within of the projected major axis, suggesting that cool dense gas resides in a narrow planer geometry surrounded by diffuse O vi gas.

UR - http://www.scopus.com/inward/record.url?scp=84951273992&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84951273992&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/815/1/22

DO - 10.1088/0004-637X/815/1/22

M3 - Article

VL - 815

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 22

ER -