Near-infrared line imaging of circumnuclear star formation in nearby active galaxies

J. K. Kotilainen; J. Reunanen; S. Laine; S. D. Ryder

doi:10.1023/A:1017054609723

Near-infrared line imaging of circumnuclear star formation in nearby active galaxies

J. K. Kotilainen^*, J. Reunanen, S. Laine, S. D. Ryder

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

We present J H K, Brγ and H₂ 1-0 S(1) imaging of the circumnuclear star forming rings in the active galaxies NGC 1097 and NGC 7771. Their clumpy morphology varies with wavelength, due to extinction, emission from hot dust and red supergiants, and several stellar generations. The H₂/Brγ ratios in the rings indicate the main excitation mechanism of the molecular gas to be UV radiation from hot young stars. Both galaxies exhibit similar small Bry equivalent widths. To explain the observations, we prefer a model of an instantaneous starburst occurring 6-7 Myr ago, as opposed to a constant star forming rate model. A gaseous nuclear bar aligned parallel to the stellar nuclear bar has been detected in NGC 1097, and we discuss the connection between the rings, bars and the fueling of nuclear activity.

Original language	English
Pages (from-to)	505-509
Number of pages	5
Journal	Astrophysics and Space Science
Volume	269
DOIs	https://doi.org/10.1023/A:1017054609723
Publication status	Published - 1 Dec 1999
Externally published	Yes

Keywords

Star Form Rate
Initial Mass Function
Active Galaxy
Radio Spectral Index
Inner Lindblad Resonance

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10.1023/A:1017054609723

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title = "Near-infrared line imaging of circumnuclear star formation in nearby active galaxies",

abstract = "We present J H K, Brγ and H2 1-0 S(1) imaging of the circumnuclear star forming rings in the active galaxies NGC 1097 and NGC 7771. Their clumpy morphology varies with wavelength, due to extinction, emission from hot dust and red supergiants, and several stellar generations. The H2/Brγ ratios in the rings indicate the main excitation mechanism of the molecular gas to be UV radiation from hot young stars. Both galaxies exhibit similar small Bry equivalent widths. To explain the observations, we prefer a model of an instantaneous starburst occurring 6-7 Myr ago, as opposed to a constant star forming rate model. A gaseous nuclear bar aligned parallel to the stellar nuclear bar has been detected in NGC 1097, and we discuss the connection between the rings, bars and the fueling of nuclear activity.",

keywords = "Star Form Rate, Initial Mass Function, Active Galaxy, Radio Spectral Index, Inner Lindblad Resonance",

author = "Kotilainen, {J. K.} and J. Reunanen and S. Laine and Ryder, {S. D.}",

year = "1999",

month = dec,

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doi = "10.1023/A:1017054609723",

language = "English",

volume = "269",

pages = "505--509",

journal = "Astrophysics and Space Science",

issn = "0004-640X",

publisher = "Springer",

}

TY - JOUR

T1 - Near-infrared line imaging of circumnuclear star formation in nearby active galaxies

AU - Kotilainen, J. K.

AU - Reunanen, J.

AU - Laine, S.

AU - Ryder, S. D.

PY - 1999/12/1

Y1 - 1999/12/1

N2 - We present J H K, Brγ and H2 1-0 S(1) imaging of the circumnuclear star forming rings in the active galaxies NGC 1097 and NGC 7771. Their clumpy morphology varies with wavelength, due to extinction, emission from hot dust and red supergiants, and several stellar generations. The H2/Brγ ratios in the rings indicate the main excitation mechanism of the molecular gas to be UV radiation from hot young stars. Both galaxies exhibit similar small Bry equivalent widths. To explain the observations, we prefer a model of an instantaneous starburst occurring 6-7 Myr ago, as opposed to a constant star forming rate model. A gaseous nuclear bar aligned parallel to the stellar nuclear bar has been detected in NGC 1097, and we discuss the connection between the rings, bars and the fueling of nuclear activity.

AB - We present J H K, Brγ and H2 1-0 S(1) imaging of the circumnuclear star forming rings in the active galaxies NGC 1097 and NGC 7771. Their clumpy morphology varies with wavelength, due to extinction, emission from hot dust and red supergiants, and several stellar generations. The H2/Brγ ratios in the rings indicate the main excitation mechanism of the molecular gas to be UV radiation from hot young stars. Both galaxies exhibit similar small Bry equivalent widths. To explain the observations, we prefer a model of an instantaneous starburst occurring 6-7 Myr ago, as opposed to a constant star forming rate model. A gaseous nuclear bar aligned parallel to the stellar nuclear bar has been detected in NGC 1097, and we discuss the connection between the rings, bars and the fueling of nuclear activity.

KW - Star Form Rate

KW - Initial Mass Function

KW - Active Galaxy

KW - Radio Spectral Index

KW - Inner Lindblad Resonance

UR - http://www.scopus.com/inward/record.url?scp=0041037014&partnerID=8YFLogxK

U2 - 10.1023/A:1017054609723

DO - 10.1023/A:1017054609723

M3 - Article

AN - SCOPUS:0041037014

SN - 0004-640X

VL - 269

SP - 505

EP - 509

JO - Astrophysics and Space Science

JF - Astrophysics and Space Science

ER -

Near-infrared line imaging of circumnuclear star formation in nearby active galaxies

Abstract

Keywords

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