Mid-infrared IRS spectroscopy of NGC 7331: A first look at the Spitzer Infrared Nearby Galaxies Survey (SINGS) legacy

J. D.T. Smith; D. A. Dale; L. Armus; B. T. Draine; D. J. Hollenbach; H. Roussel; G. Helou; R. C. Kennicutt; A. Li; G. J. Bendo; D. Calzetti; C. W. Engelbracht; K. D. Gordon; T. H. Jarrett; L. Kewley; C. Leitherer; S. Malhotra; M. J. Meyer; E. J. Murphy; M. W. Regan; G. H. Rieke; M. J. Rieke; M. D. Thornley; F. Walter; M. G. Wolfire

doi:10.1086/423133

Mid-infrared IRS spectroscopy of NGC 7331: A first look at the Spitzer Infrared Nearby Galaxies Survey (SINGS) legacy

J. D.T. Smith, D. A. Dale, L. Armus, B. T. Draine, D. J. Hollenbach, H. Roussel, G. Helou, R. C. Kennicutt, A. Li, G. J. Bendo, D. Calzetti, C. W. Engelbracht, K. D. Gordon, T. H. Jarrett, L. Kewley, C. Leitherer, S. Malhotra, M. J. Meyer, E. J. Murphy, M. W. ReganG. H. Rieke, M. J. Rieke, M. D. Thornley, F. Walter, M. G. Wolfire

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Abstract

The nearby spiral galaxy NGC 7331 was spectrally mapped from 5 to 38 μm using all modules of Spitzer's Infrared Spectrograph (IRS). A strong new dust emission feature, presumed due to polycyclic aromatic hydrocarbons, was discovered at 17.1 μm. The feature's intensity is nearly half that of the ubiquitous 11.3 μm band. The 7-14 μm spectral maps revealed significant variation in the 7.7 and 11.3 μm PAH features between the stellar ring and nucleus. Weak [O IV] 25.9 μm line emission was found to be centrally concentrated in the nucleus, with an observed strength of over 10% of the combined neon line flux, indicating an AGN or unusually active massive star photoionization. Two [S III] lines fix the characteristic electron density in the H II regions at n_e ≲ 200 cm^-3. Three detected H₂ rotational lines, tracing warm molecular gas, together with the observed IR continuum, are difficult to match with standard photodissociation region (PDR) models. Either additional PDR heating or shocks are required to simultaneously match lines and continuum.

Original language	English (US)
Pages (from-to)	199-203
Number of pages	5
Journal	Astrophysical Journal, Supplement Series
Volume	154
Issue number	1
DOIs	https://doi.org/10.1086/423133
State	Published - Sep 2004
Externally published	Yes

Keywords

Dust, extinction
Galaxies: ISM
Galaxies: individual (NGC 7331)
Infrared: galaxies
Line: identification
Techniques: spectroscopic

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1086/423133

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Smith, J. D. T., Dale, D. A., Armus, L., Draine, B. T., Hollenbach, D. J., Roussel, H., Helou, G., Kennicutt, R. C., Li, A., Bendo, G. J., Calzetti, D., Engelbracht, C. W., Gordon, K. D., Jarrett, T. H., Kewley, L., Leitherer, C., Malhotra, S., Meyer, M. J., Murphy, E. J., ... Wolfire, M. G. (2004). Mid-infrared IRS spectroscopy of NGC 7331: A first look at the Spitzer Infrared Nearby Galaxies Survey (SINGS) legacy. Astrophysical Journal, Supplement Series, 154(1), 199-203. https://doi.org/10.1086/423133

Smith, JDT, Dale, DA, Armus, L, Draine, BT, Hollenbach, DJ, Roussel, H, Helou, G, Kennicutt, RC, Li, A, Bendo, GJ, Calzetti, D, Engelbracht, CW, Gordon, KD, Jarrett, TH, Kewley, L, Leitherer, C, Malhotra, S, Meyer, MJ, Murphy, EJ, Regan, MW, Rieke, GH, Rieke, MJ, Thornley, MD, Walter, F & Wolfire, MG 2004, 'Mid-infrared IRS spectroscopy of NGC 7331: A first look at the Spitzer Infrared Nearby Galaxies Survey (SINGS) legacy', Astrophysical Journal, Supplement Series, vol. 154, no. 1, pp. 199-203. https://doi.org/10.1086/423133

@article{32c1f2621f02488295e42f2dfc823313,

title = "Mid-infrared IRS spectroscopy of NGC 7331: A first look at the Spitzer Infrared Nearby Galaxies Survey (SINGS) legacy",

abstract = "The nearby spiral galaxy NGC 7331 was spectrally mapped from 5 to 38 μm using all modules of Spitzer's Infrared Spectrograph (IRS). A strong new dust emission feature, presumed due to polycyclic aromatic hydrocarbons, was discovered at 17.1 μm. The feature's intensity is nearly half that of the ubiquitous 11.3 μm band. The 7-14 μm spectral maps revealed significant variation in the 7.7 and 11.3 μm PAH features between the stellar ring and nucleus. Weak [O IV] 25.9 μm line emission was found to be centrally concentrated in the nucleus, with an observed strength of over 10% of the combined neon line flux, indicating an AGN or unusually active massive star photoionization. Two [S III] lines fix the characteristic electron density in the H II regions at ne ≲ 200 cm-3. Three detected H2 rotational lines, tracing warm molecular gas, together with the observed IR continuum, are difficult to match with standard photodissociation region (PDR) models. Either additional PDR heating or shocks are required to simultaneously match lines and continuum.",

keywords = "Dust, extinction, Galaxies: ISM, Galaxies: individual (NGC 7331), Infrared: galaxies, Line: identification, Techniques: spectroscopic",

author = "Smith, {J. D.T.} and Dale, {D. A.} and L. Armus and Draine, {B. T.} and Hollenbach, {D. J.} and H. Roussel and G. Helou and Kennicutt, {R. C.} and A. Li and Bendo, {G. J.} and D. Calzetti and Engelbracht, {C. W.} and Gordon, {K. D.} and Jarrett, {T. H.} and L. Kewley and C. Leitherer and S. Malhotra and Meyer, {M. J.} and Murphy, {E. J.} and Regan, {M. W.} and Rieke, {G. H.} and Rieke, {M. J.} and Thornley, {M. D.} and F. Walter and Wolfire, {M. G.}",

year = "2004",

month = sep,

doi = "10.1086/423133",

language = "English (US)",

volume = "154",

pages = "199--203",

journal = "Astrophysical Journal, Supplement Series",

issn = "0067-0049",

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number = "1",

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T1 - Mid-infrared IRS spectroscopy of NGC 7331

T2 - A first look at the Spitzer Infrared Nearby Galaxies Survey (SINGS) legacy

AU - Smith, J. D.T.

AU - Dale, D. A.

AU - Armus, L.

AU - Draine, B. T.

AU - Hollenbach, D. J.

AU - Roussel, H.

AU - Helou, G.

AU - Kennicutt, R. C.

AU - Li, A.

AU - Bendo, G. J.

AU - Calzetti, D.

AU - Engelbracht, C. W.

AU - Gordon, K. D.

AU - Jarrett, T. H.

AU - Kewley, L.

AU - Leitherer, C.

AU - Malhotra, S.

AU - Meyer, M. J.

AU - Murphy, E. J.

AU - Regan, M. W.

AU - Rieke, G. H.

AU - Rieke, M. J.

AU - Thornley, M. D.

AU - Walter, F.

AU - Wolfire, M. G.

PY - 2004/9

Y1 - 2004/9

N2 - The nearby spiral galaxy NGC 7331 was spectrally mapped from 5 to 38 μm using all modules of Spitzer's Infrared Spectrograph (IRS). A strong new dust emission feature, presumed due to polycyclic aromatic hydrocarbons, was discovered at 17.1 μm. The feature's intensity is nearly half that of the ubiquitous 11.3 μm band. The 7-14 μm spectral maps revealed significant variation in the 7.7 and 11.3 μm PAH features between the stellar ring and nucleus. Weak [O IV] 25.9 μm line emission was found to be centrally concentrated in the nucleus, with an observed strength of over 10% of the combined neon line flux, indicating an AGN or unusually active massive star photoionization. Two [S III] lines fix the characteristic electron density in the H II regions at ne ≲ 200 cm-3. Three detected H2 rotational lines, tracing warm molecular gas, together with the observed IR continuum, are difficult to match with standard photodissociation region (PDR) models. Either additional PDR heating or shocks are required to simultaneously match lines and continuum.

AB - The nearby spiral galaxy NGC 7331 was spectrally mapped from 5 to 38 μm using all modules of Spitzer's Infrared Spectrograph (IRS). A strong new dust emission feature, presumed due to polycyclic aromatic hydrocarbons, was discovered at 17.1 μm. The feature's intensity is nearly half that of the ubiquitous 11.3 μm band. The 7-14 μm spectral maps revealed significant variation in the 7.7 and 11.3 μm PAH features between the stellar ring and nucleus. Weak [O IV] 25.9 μm line emission was found to be centrally concentrated in the nucleus, with an observed strength of over 10% of the combined neon line flux, indicating an AGN or unusually active massive star photoionization. Two [S III] lines fix the characteristic electron density in the H II regions at ne ≲ 200 cm-3. Three detected H2 rotational lines, tracing warm molecular gas, together with the observed IR continuum, are difficult to match with standard photodissociation region (PDR) models. Either additional PDR heating or shocks are required to simultaneously match lines and continuum.

KW - Dust, extinction

KW - Galaxies: ISM

KW - Galaxies: individual (NGC 7331)

KW - Infrared: galaxies

KW - Line: identification

KW - Techniques: spectroscopic

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U2 - 10.1086/423133

DO - 10.1086/423133

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AN - SCOPUS:5644290950

SN - 0067-0049

VL - 154

SP - 199

EP - 203

JO - Astrophysical Journal, Supplement Series

JF - Astrophysical Journal, Supplement Series

IS - 1

ER -

Mid-infrared IRS spectroscopy of NGC 7331: A first look at the Spitzer Infrared Nearby Galaxies Survey (SINGS) legacy

Abstract

Keywords

ASJC Scopus subject areas

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