Spitzer mid-infrared spectroscopy of 70 μm-selected distant luminous infrared galaxies

Kate Brand, Dan W. Weedman, Vandana Desai, Emeric Le Floc'h, Lee Armus, Arjun Dey, Jim R. Houck, Buell Tomasson Jannuzi, Howard A. Smith, B. T. Soifer

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

We present mid-infrared spectroscopy obtained with the Spitzer Space Telescope of a sample of 11 optically faint, infrared luminous galaxies selected from a Spitzer MIPS 70 μm imaging survey of the NDWFS Bootes field. These are the first Spitzer IRS spectra presented of distant 70 μm-selected sources. All the galaxies lie at redshifts 0.3 < z < 1.3 and have very large infrared luminosities of LIR ∼ (0.1-17) × 10 12 Z. Seven of the galaxies exhibit strong emission features attributed to polycyclic aromatic hydrocarbons (PAHs). The average IRS spectrum of these sources is characteristic of classical starburst galaxies but with much larger infrared luminosities. The PAH luminosities of vL v(7.7 μm) ∼ (0.4-7) × 1011 L imply star formation rates of ∼40-720 M yr-1. Four of the galaxies show deep 9.7 μm silicate absorption features and no significant PAH emission features (6.2 μm equivalent widths <0.03 μm). The large infrared luminosities and low vfv(70 μm)/vf v(24 μm) flux density ratios suggests that these sources have AGNs as the dominant origin of their large mid-infrared luminosities, although deeply embedded but luminous star-bursts cannot be ruled out. If the absorbed sources are AGN-dominated, a significant fraction of all far-infrared bright, optically faint sources may be dominated by AGNs.

Original languageEnglish (US)
Pages (from-to)119-127
Number of pages9
JournalAstrophysical Journal
Volume673
Issue number1
DOIs
StatePublished - Jan 20 2008
Externally publishedYes

Fingerprint

infrared spectroscopy
luminosity
galaxies
polycyclic aromatic hydrocarbons
Indian spacecraft
PAH
Space Infrared Telescope Facility
starburst galaxies
star formation rate
silicates
bursts
silicate
flux density
stars

Keywords

  • Galaxies: active
  • Galaxies: starburst
  • Infrared: galaxies
  • Quasars: general

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Brand, K., Weedman, D. W., Desai, V., Le Floc'h, E., Armus, L., Dey, A., ... Soifer, B. T. (2008). Spitzer mid-infrared spectroscopy of 70 μm-selected distant luminous infrared galaxies. Astrophysical Journal, 673(1), 119-127. https://doi.org/10.1086/523938

Spitzer mid-infrared spectroscopy of 70 μm-selected distant luminous infrared galaxies. / Brand, Kate; Weedman, Dan W.; Desai, Vandana; Le Floc'h, Emeric; Armus, Lee; Dey, Arjun; Houck, Jim R.; Jannuzi, Buell Tomasson; Smith, Howard A.; Soifer, B. T.

In: Astrophysical Journal, Vol. 673, No. 1, 20.01.2008, p. 119-127.

Research output: Contribution to journalArticle

Brand, K, Weedman, DW, Desai, V, Le Floc'h, E, Armus, L, Dey, A, Houck, JR, Jannuzi, BT, Smith, HA & Soifer, BT 2008, 'Spitzer mid-infrared spectroscopy of 70 μm-selected distant luminous infrared galaxies', Astrophysical Journal, vol. 673, no. 1, pp. 119-127. https://doi.org/10.1086/523938
Brand K, Weedman DW, Desai V, Le Floc'h E, Armus L, Dey A et al. Spitzer mid-infrared spectroscopy of 70 μm-selected distant luminous infrared galaxies. Astrophysical Journal. 2008 Jan 20;673(1):119-127. https://doi.org/10.1086/523938
Brand, Kate ; Weedman, Dan W. ; Desai, Vandana ; Le Floc'h, Emeric ; Armus, Lee ; Dey, Arjun ; Houck, Jim R. ; Jannuzi, Buell Tomasson ; Smith, Howard A. ; Soifer, B. T. / Spitzer mid-infrared spectroscopy of 70 μm-selected distant luminous infrared galaxies. In: Astrophysical Journal. 2008 ; Vol. 673, No. 1. pp. 119-127.
@article{b0356dabb51f441c8259b732e85c0729,
title = "Spitzer mid-infrared spectroscopy of 70 μm-selected distant luminous infrared galaxies",
abstract = "We present mid-infrared spectroscopy obtained with the Spitzer Space Telescope of a sample of 11 optically faint, infrared luminous galaxies selected from a Spitzer MIPS 70 μm imaging survey of the NDWFS Bootes field. These are the first Spitzer IRS spectra presented of distant 70 μm-selected sources. All the galaxies lie at redshifts 0.3 < z < 1.3 and have very large infrared luminosities of LIR ∼ (0.1-17) × 10 12 Z⊙. Seven of the galaxies exhibit strong emission features attributed to polycyclic aromatic hydrocarbons (PAHs). The average IRS spectrum of these sources is characteristic of classical starburst galaxies but with much larger infrared luminosities. The PAH luminosities of vL v(7.7 μm) ∼ (0.4-7) × 1011 L⊙ imply star formation rates of ∼40-720 M⊙ yr-1. Four of the galaxies show deep 9.7 μm silicate absorption features and no significant PAH emission features (6.2 μm equivalent widths <0.03 μm). The large infrared luminosities and low vfv(70 μm)/vf v(24 μm) flux density ratios suggests that these sources have AGNs as the dominant origin of their large mid-infrared luminosities, although deeply embedded but luminous star-bursts cannot be ruled out. If the absorbed sources are AGN-dominated, a significant fraction of all far-infrared bright, optically faint sources may be dominated by AGNs.",
keywords = "Galaxies: active, Galaxies: starburst, Infrared: galaxies, Quasars: general",
author = "Kate Brand and Weedman, {Dan W.} and Vandana Desai and {Le Floc'h}, Emeric and Lee Armus and Arjun Dey and Houck, {Jim R.} and Jannuzi, {Buell Tomasson} and Smith, {Howard A.} and Soifer, {B. T.}",
year = "2008",
month = "1",
day = "20",
doi = "10.1086/523938",
language = "English (US)",
volume = "673",
pages = "119--127",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Spitzer mid-infrared spectroscopy of 70 μm-selected distant luminous infrared galaxies

AU - Brand, Kate

AU - Weedman, Dan W.

AU - Desai, Vandana

AU - Le Floc'h, Emeric

AU - Armus, Lee

AU - Dey, Arjun

AU - Houck, Jim R.

AU - Jannuzi, Buell Tomasson

AU - Smith, Howard A.

AU - Soifer, B. T.

PY - 2008/1/20

Y1 - 2008/1/20

N2 - We present mid-infrared spectroscopy obtained with the Spitzer Space Telescope of a sample of 11 optically faint, infrared luminous galaxies selected from a Spitzer MIPS 70 μm imaging survey of the NDWFS Bootes field. These are the first Spitzer IRS spectra presented of distant 70 μm-selected sources. All the galaxies lie at redshifts 0.3 < z < 1.3 and have very large infrared luminosities of LIR ∼ (0.1-17) × 10 12 Z⊙. Seven of the galaxies exhibit strong emission features attributed to polycyclic aromatic hydrocarbons (PAHs). The average IRS spectrum of these sources is characteristic of classical starburst galaxies but with much larger infrared luminosities. The PAH luminosities of vL v(7.7 μm) ∼ (0.4-7) × 1011 L⊙ imply star formation rates of ∼40-720 M⊙ yr-1. Four of the galaxies show deep 9.7 μm silicate absorption features and no significant PAH emission features (6.2 μm equivalent widths <0.03 μm). The large infrared luminosities and low vfv(70 μm)/vf v(24 μm) flux density ratios suggests that these sources have AGNs as the dominant origin of their large mid-infrared luminosities, although deeply embedded but luminous star-bursts cannot be ruled out. If the absorbed sources are AGN-dominated, a significant fraction of all far-infrared bright, optically faint sources may be dominated by AGNs.

AB - We present mid-infrared spectroscopy obtained with the Spitzer Space Telescope of a sample of 11 optically faint, infrared luminous galaxies selected from a Spitzer MIPS 70 μm imaging survey of the NDWFS Bootes field. These are the first Spitzer IRS spectra presented of distant 70 μm-selected sources. All the galaxies lie at redshifts 0.3 < z < 1.3 and have very large infrared luminosities of LIR ∼ (0.1-17) × 10 12 Z⊙. Seven of the galaxies exhibit strong emission features attributed to polycyclic aromatic hydrocarbons (PAHs). The average IRS spectrum of these sources is characteristic of classical starburst galaxies but with much larger infrared luminosities. The PAH luminosities of vL v(7.7 μm) ∼ (0.4-7) × 1011 L⊙ imply star formation rates of ∼40-720 M⊙ yr-1. Four of the galaxies show deep 9.7 μm silicate absorption features and no significant PAH emission features (6.2 μm equivalent widths <0.03 μm). The large infrared luminosities and low vfv(70 μm)/vf v(24 μm) flux density ratios suggests that these sources have AGNs as the dominant origin of their large mid-infrared luminosities, although deeply embedded but luminous star-bursts cannot be ruled out. If the absorbed sources are AGN-dominated, a significant fraction of all far-infrared bright, optically faint sources may be dominated by AGNs.

KW - Galaxies: active

KW - Galaxies: starburst

KW - Infrared: galaxies

KW - Quasars: general

UR - http://www.scopus.com/inward/record.url?scp=40249100225&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=40249100225&partnerID=8YFLogxK

U2 - 10.1086/523938

DO - 10.1086/523938

M3 - Article

AN - SCOPUS:40249100225

VL - 673

SP - 119

EP - 127

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

ER -