Effects of photon trapping on the Lyα properties of star-forming galaxies

Hidenobu Yajima, Yuexing Cindy Li

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Recent observations show that a large number of Lya emitters at high redshift z > 3 have unusually high Lya equivalent widths (EW > 400 Å). However, the origin of these high EWs is an open question. Here, we investigate the impacts of photon trapping on the Lya EW and other properties by tracking the Lyα radiative transfer in spherical galactic clouds. We find that the delayed escape of the Lya photons can change the Lya properties significantly. During the transition phase from optically thick to optically thin where the Lyα photons can escape simultaneously, the EW can be boosted to ~1000 Å, the Lyα luminosity can be increased by a factor of a few, and the line profile can be significantly broadened. The boost factor appears to depend on the galaxy properties such as mass and star formation rate and time-scale; therefore, future investigation combing 3D Lya radiative transfer calculations with cosmological simulations of galaxy formation and evolution is needed to fully understand the Lya properties of early star-forming galaxies. .

Original languageEnglish (US)
Pages (from-to)3962-3968
Number of pages7
JournalMonthly Notices of the Royal Astronomical Society
Volume437
Issue number4
DOIs
StatePublished - Feb 1 2014

Fingerprint

radiative transfer
trapping
galaxies
stars
photons
phase transition
escape
timescale
early stars
galactic evolution
star formation rate
acceleration (physics)
simulation
emitters
luminosity
effect
profiles
calculation
rate

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

@article{773b4db91eb344daa401d3709aa6ab24,
title = "Effects of photon trapping on the Lyα properties of star-forming galaxies",
abstract = "Recent observations show that a large number of Lya emitters at high redshift z > 3 have unusually high Lya equivalent widths (EW > 400 {\AA}). However, the origin of these high EWs is an open question. Here, we investigate the impacts of photon trapping on the Lya EW and other properties by tracking the Lyα radiative transfer in spherical galactic clouds. We find that the delayed escape of the Lya photons can change the Lya properties significantly. During the transition phase from optically thick to optically thin where the Lyα photons can escape simultaneously, the EW can be boosted to ~1000 {\AA}, the Lyα luminosity can be increased by a factor of a few, and the line profile can be significantly broadened. The boost factor appears to depend on the galaxy properties such as mass and star formation rate and time-scale; therefore, future investigation combing 3D Lya radiative transfer calculations with cosmological simulations of galaxy formation and evolution is needed to fully understand the Lya properties of early star-forming galaxies. .",
author = "Hidenobu Yajima and Li, {Yuexing Cindy}",
year = "2014",
month = "2",
day = "1",
doi = "10.1093/mnras/stt2205",
language = "English (US)",
volume = "437",
pages = "3962--3968",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "4",

}

Effects of photon trapping on the Lyα properties of star-forming galaxies. / Yajima, Hidenobu; Li, Yuexing Cindy.

In: Monthly Notices of the Royal Astronomical Society, Vol. 437, No. 4, 01.02.2014, p. 3962-3968.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Effects of photon trapping on the Lyα properties of star-forming galaxies

AU - Yajima, Hidenobu

AU - Li, Yuexing Cindy

PY - 2014/2/1

Y1 - 2014/2/1

N2 - Recent observations show that a large number of Lya emitters at high redshift z > 3 have unusually high Lya equivalent widths (EW > 400 Å). However, the origin of these high EWs is an open question. Here, we investigate the impacts of photon trapping on the Lya EW and other properties by tracking the Lyα radiative transfer in spherical galactic clouds. We find that the delayed escape of the Lya photons can change the Lya properties significantly. During the transition phase from optically thick to optically thin where the Lyα photons can escape simultaneously, the EW can be boosted to ~1000 Å, the Lyα luminosity can be increased by a factor of a few, and the line profile can be significantly broadened. The boost factor appears to depend on the galaxy properties such as mass and star formation rate and time-scale; therefore, future investigation combing 3D Lya radiative transfer calculations with cosmological simulations of galaxy formation and evolution is needed to fully understand the Lya properties of early star-forming galaxies. .

AB - Recent observations show that a large number of Lya emitters at high redshift z > 3 have unusually high Lya equivalent widths (EW > 400 Å). However, the origin of these high EWs is an open question. Here, we investigate the impacts of photon trapping on the Lya EW and other properties by tracking the Lyα radiative transfer in spherical galactic clouds. We find that the delayed escape of the Lya photons can change the Lya properties significantly. During the transition phase from optically thick to optically thin where the Lyα photons can escape simultaneously, the EW can be boosted to ~1000 Å, the Lyα luminosity can be increased by a factor of a few, and the line profile can be significantly broadened. The boost factor appears to depend on the galaxy properties such as mass and star formation rate and time-scale; therefore, future investigation combing 3D Lya radiative transfer calculations with cosmological simulations of galaxy formation and evolution is needed to fully understand the Lya properties of early star-forming galaxies. .

UR - http://www.scopus.com/inward/record.url?scp=84891353366&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84891353366&partnerID=8YFLogxK

U2 - 10.1093/mnras/stt2205

DO - 10.1093/mnras/stt2205

M3 - Article

VL - 437

SP - 3962

EP - 3968

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -