Molecular hydrogen and Paα emission in cooling flow galaxies

Heino Falcke; M. J. Rieke; G. H. Rieke; Chris Simpson; Andrew S. Wilson

doi:10.1086/311176

Molecular hydrogen and Paα emission in cooling flow galaxies

Heino Falcke, M. J. Rieke, G. H. Rieke, Chris Simpson, Andrew S. Wilson

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34 Scopus citations

Abstract

We present near-infrared spectra that were obtained in order to search for Paα and molecular hydrogen lines in edge-darkened (FR I-type) radio galaxies with bright Ha emission in the redshift range 0.0535 < z < 0.15. We find that all three galaxies in our sample (PKS 0745-191, PKS 1346+26, and PKS 2322-12) associated with strong cooling flows also have strong Paα and H₂ 1-0 5(1) through S(5) emission, while other radio galaxies do not. Together with earlier observations, this confirms the claims that cooling flow galaxies are copious emitters of molecular hydrogen with large H₂ 1-0 S(3)/Paα ratios in the range 0.5-2. The emission is centrally concentrated within the inner few kiloparsecs and could come from warm (T ≃ 1000-1500 K) molecular material that is being deposited by the cooling flow. We speculate that the H₂ emission could be related to the interaction between the jets and this molecular gas.

Original language	English (US)
Pages (from-to)	L155-L158
Journal	Astrophysical Journal
Volume	494
Issue number	2 PART II
DOIs	https://doi.org/10.1086/311176
State	Published - 1998

Keywords

Cooling flows
Galaxies: clusters: general
Galaxies: elliptical and lenticular, cD galaxies: ISM
Galaxies: jets

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1086/311176

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@article{0f8a01475dda49769b13e32d533e8a0a,

title = "Molecular hydrogen and Paα emission in cooling flow galaxies",

abstract = "We present near-infrared spectra that were obtained in order to search for Paα and molecular hydrogen lines in edge-darkened (FR I-type) radio galaxies with bright Ha emission in the redshift range 0.0535 < z < 0.15. We find that all three galaxies in our sample (PKS 0745-191, PKS 1346+26, and PKS 2322-12) associated with strong cooling flows also have strong Paα and H2 1-0 5(1) through S(5) emission, while other radio galaxies do not. Together with earlier observations, this confirms the claims that cooling flow galaxies are copious emitters of molecular hydrogen with large H2 1-0 S(3)/Paα ratios in the range 0.5-2. The emission is centrally concentrated within the inner few kiloparsecs and could come from warm (T ≃ 1000-1500 K) molecular material that is being deposited by the cooling flow. We speculate that the H2 emission could be related to the interaction between the jets and this molecular gas.",

keywords = "Cooling flows, Galaxies: clusters: general, Galaxies: elliptical and lenticular, cD galaxies: ISM, Galaxies: jets",

author = "Heino Falcke and Rieke, {M. J.} and Rieke, {G. H.} and Chris Simpson and Wilson, {Andrew S.}",

year = "1998",

doi = "10.1086/311176",

language = "English (US)",

volume = "494",

pages = "L155--L158",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "IOP Publishing Ltd.",

number = "2 PART II",

}

TY - JOUR

T1 - Molecular hydrogen and Paα emission in cooling flow galaxies

AU - Falcke, Heino

AU - Rieke, M. J.

AU - Rieke, G. H.

AU - Simpson, Chris

AU - Wilson, Andrew S.

PY - 1998

Y1 - 1998

N2 - We present near-infrared spectra that were obtained in order to search for Paα and molecular hydrogen lines in edge-darkened (FR I-type) radio galaxies with bright Ha emission in the redshift range 0.0535 < z < 0.15. We find that all three galaxies in our sample (PKS 0745-191, PKS 1346+26, and PKS 2322-12) associated with strong cooling flows also have strong Paα and H2 1-0 5(1) through S(5) emission, while other radio galaxies do not. Together with earlier observations, this confirms the claims that cooling flow galaxies are copious emitters of molecular hydrogen with large H2 1-0 S(3)/Paα ratios in the range 0.5-2. The emission is centrally concentrated within the inner few kiloparsecs and could come from warm (T ≃ 1000-1500 K) molecular material that is being deposited by the cooling flow. We speculate that the H2 emission could be related to the interaction between the jets and this molecular gas.

AB - We present near-infrared spectra that were obtained in order to search for Paα and molecular hydrogen lines in edge-darkened (FR I-type) radio galaxies with bright Ha emission in the redshift range 0.0535 < z < 0.15. We find that all three galaxies in our sample (PKS 0745-191, PKS 1346+26, and PKS 2322-12) associated with strong cooling flows also have strong Paα and H2 1-0 5(1) through S(5) emission, while other radio galaxies do not. Together with earlier observations, this confirms the claims that cooling flow galaxies are copious emitters of molecular hydrogen with large H2 1-0 S(3)/Paα ratios in the range 0.5-2. The emission is centrally concentrated within the inner few kiloparsecs and could come from warm (T ≃ 1000-1500 K) molecular material that is being deposited by the cooling flow. We speculate that the H2 emission could be related to the interaction between the jets and this molecular gas.

KW - Cooling flows

KW - Galaxies: clusters: general

KW - Galaxies: elliptical and lenticular, cD galaxies: ISM

KW - Galaxies: jets

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U2 - 10.1086/311176

DO - 10.1086/311176

M3 - Article

AN - SCOPUS:22044454786

SN - 0004-637X

VL - 494

SP - L155-L158

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2 PART II

ER -

Molecular hydrogen and Paα emission in cooling flow galaxies

Abstract

Keywords

ASJC Scopus subject areas

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