J/ApJ/705/885 PAH in galaxies at z∼0.1 (O'Dowd+, 2009)
Polycyclic aromatic hydrocarbons in galaxies at z ∼ 0.1: the effect of star
formation and active galactic nuclei.
O'Dowd M.J., Schiminovich D., Johnson B.D., Treyer M.A., Martin C.D.,
Wyder T.K., Charlot S., Heckman T.M., Martins L.P., Seibert M.,
van der Hulst J.M.
<Astrophys. J., 705, 885-898 (2009)>
=2009ApJ...705..885O 2009ApJ...705..885O
ADC_Keywords: Galaxies, IR ; Spectra, infrared ; Spectroscopy ; Line Profiles ;
Interstellar medium
Keywords: galaxies: active - galaxies: ISM - ISM: lines and bands -
ISM: molecules - infrared: galaxies - techniques: spectroscopic
Abstract:
We present the analysis of the polycyclic aromatic hydrocarbon (PAH)
spectra of a sample of 92 typical star-forming galaxies at 0.03<z<0.2
observed with the Spitzer intensified Reticon spectrograph (IRS). We
compare the relative strengths of PAH emission features with Sloan
Digital Sky Survey optical diagnostics to probe the relationship
between PAH grain properties and star formation and active galactic
nuclei (AGNs) activity. Short-to-long wavelength PAH ratios, and in
particular the 7.7um-to-11.3um feature ratio, are strongly correlated
with the star formation diagnostics Dn(4000) and Hα equivalent
width, increasing with younger stellar populations. This ratio also
shows a significant difference between active and non-active galaxies,
with the active galaxies exhibiting weaker 7.7um emission. A hard
radiation field as measured by [OIII]/Hβ and
[NeIII]15.6um/[NeII]12.8um effects PAH ratios differently
depending on whether this field results from starburst activity or an
AGN. Our results are consistent with a picture in which larger PAH
molecules grow more efficiently in richer media and in which smaller
PAH molecules are preferentially destroyed by the AGN.
Description:
The full details of the Spitzer SDSS GALEX Spectroscopic Survey
(SSGSS) sample selection, observations, and data reduction are
reported in M. J. O'Dowd et al. (2011, Cat. J/ApJ/741/79). All data
were taken during Spitzer IRS campaign 37.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 283 92 Dust features, extinction, and line strengths
from PAHFIT analysis
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See also:
J/ApJ/741/79 : The Spitzer-SDSS-GALEX Spectroscopic Survey (O'Dowd+, 2011)
J/A+A/527/A109 : Dust and PAH emission SEDs of disk galaxies (Popescu+, 2011)
J/A+A/514/A5 : PAH luminous galaxies at z∼1 (Takagi+, 2010)
J/A+A/507/713 : Galaxies with strong PAH emission (Haas+, 2009)
J/ApJ/686/127 : Starbursts luminosities based on PAH (Weedman+, 2008)
J/ApJ/656/770 : Mid-IR spectrum of star-forming galaxies (Smith+, 2007)
J/A+A/319/318 : PAH hypothesis (Pauzat+ 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- SSGSS SSGSS (Spitzer SDSS GALEX Spectroscopic Survey)
number
5- 14 F10.6 deg RAdeg Right Ascention in decimal degrees (J2000)
16- 25 F10.6 deg DEdeg Declination in decimal degrees (J2000)
27- 34 E8.2 W/m2 F6.2 ?=0 The 6.2um feature intensity
36- 43 E8.2 W/m2 e_F6.2 ?=9.99E-99 Uncertainty in F6.2 (1)
45- 52 E8.2 W/m2 F7.7 ?=0 The 7.7um feature intensity
54- 61 E8.2 W/m2 e_F7.7 ?=9.99E-99 Uncertainty in F7.7 (1)
63- 70 E8.2 W/m2 F8.3 ?=0 The 8.3um feature intensity
72- 79 E8.2 W/m2 e_F8.3 ?=9.99E-99 Uncertainty in F8.3 (1)
81- 88 E8.2 W/m2 F8.6 ?=0 The 8.6um feature intensity
90- 97 E8.2 W/m2 e_F8.6 ?=9.99E-99 Uncertainty in F8.6 (1)
99-106 E8.2 W/m2 F11.3 ?=0 The 11.3um feature intensity
108-115 E8.2 W/m2 e_F11.3 ?=9.99E-99 Uncertainty in F11.3 (1)
117-124 E8.2 W/m2 F12.0 ?=0 The 12.0um feature intensity
126-133 E8.2 W/m2 e_F12.0 ?=9.99E-99 Uncertainty in F12.0 (1)
135-142 E8.2 W/m2 F12.6 ?=0 The 12.6um feature intensity
144-151 E8.2 W/m2 e_F12.6 ?=9.99E-99 Uncertainty in F12.6 (1)
153-160 E8.2 W/m2 F13.6 ?=0 The 13.6um feature intensity
162-169 E8.2 W/m2 e_F13.6 ?=9.99E-99 Uncertainty in F13.6 (1)
171-178 E8.2 W/m2 F14.2 ?=0 The 14.2um feature intensity
180-187 E8.2 W/m2 e_F14.2 ?=9.99E-99 Uncertainty in F14.2 (1)
189-196 E8.2 W/m2 F16.4 ?=0 The 16.4um feature intensity
198-205 E8.2 W/m2 e_F16.4 ?=9.99E-99 Uncertainty in F16.4 (1)
207-214 E8.2 W/m2 F17 ?=0 The 17um feature intensity
216-223 E8.2 W/m2 e_F17 ?=9.99E-99 Uncertainty in F17 (1)
225-232 E8.2 W/m2 F17.4 ?=0 The 17.4um feature intensity
234-241 E8.2 W/m2 e_F17.4 ?=9.99E-99 Uncertainty in F17.4 (1)
243-247 F5.3 --- tau9.7 ?=0.0 Optical depth of dust extinction at 9.7um
249-256 E8.2 W/m2 NeII ? The [NeII] line intensity (2)
258-265 E8.2 W/m2 e_NeII ? Uncertainty in NeII
267-274 E8.2 W/m2 NeIII ? The [NeIII] line intensity (2)
276-283 E8.2 W/m2 e_NeIII ? Uncertainty in NeIII (1)
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Note (1): Uncertainties values of 9.99E-99 represent NaN values, indicating
no fitted emission in the corresponding PAH feature.
Note (2): [NeII] and [NeIII] line intensities are from hi-res spectroscopy,
and so are only presented for 32 sources with Short-High observations
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 05-Dec-2011