The FR-I radio galaxies NGC 315 and NGC 4261 observed with ASCA

Yukari Matsumoto; Yasushi Fukazawa; Kazuhiro Nakazawa; Naoko Iyomoto; Kazuo Makishima

doi:10.1093/pasj/53.3.475

The FR-I radio galaxies NGC 315 and NGC 4261 observed with ASCA

Yukari Matsumoto
, Yasushi Fukazawa
, Kazuhiro Nakazawa
, Naoko Iyomoto
, Kazuo Makishima

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

10 Citations (Scopus)

Abstract

FR-I radio galaxies NGC 315 and NGC 4261 were observed in X-rays with ASCA for ∼ 37 ks and ∼ 54 ks, respectively. Hard X-ray emission from a point-like source at the nucleus was detected at a 2-10 keV luminosity of 3.1 × 10⁴¹ and 9.2 × 10⁴⁰ erg s^-1, respectively, for assumed distances of 66 Mpc and 29 Mpc (for H₀ = 75 km s^-1 Mpc^-1). The 2-10 keV spectra of NGC 315 and NGC 4261 were both fitted successfully with a power-law of photon index 2.02 ± 0.34 and 1.45 ± 0.11, respectively, plus emission from hot gas. The NGC 315 nucleus is mildly absorbed. No X-ray variability was detected from either object, with typical upper limits of several tens per cent. These results imply the presence of a low-luminosity active galactic nucleus in both galaxies, and reconfirm the previous recognition that the FR-I nuclei are significantly less X-ray luminous than the FR-II ones.

Original language	English
Pages (from-to)	475-481
Number of pages	7
Journal	Publications of the Astronomical Society of Japan
Volume	53
Issue number	3
DOIs	https://doi.org/10.1093/pasj/53.3.475
Publication status	Published - Jun 25 2001
Externally published	Yes

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

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10.1093/pasj/53.3.475

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@article{12635870f0f14011abb3a59768fc99a2,

title = "The FR-I radio galaxies NGC 315 and NGC 4261 observed with ASCA",

abstract = "FR-I radio galaxies NGC 315 and NGC 4261 were observed in X-rays with ASCA for ∼ 37 ks and ∼ 54 ks, respectively. Hard X-ray emission from a point-like source at the nucleus was detected at a 2-10 keV luminosity of 3.1 × 1041 and 9.2 × 1040 erg s-1, respectively, for assumed distances of 66 Mpc and 29 Mpc (for H0 = 75 km s-1 Mpc-1). The 2-10 keV spectra of NGC 315 and NGC 4261 were both fitted successfully with a power-law of photon index 2.02 ± 0.34 and 1.45 ± 0.11, respectively, plus emission from hot gas. The NGC 315 nucleus is mildly absorbed. No X-ray variability was detected from either object, with typical upper limits of several tens per cent. These results imply the presence of a low-luminosity active galactic nucleus in both galaxies, and reconfirm the previous recognition that the FR-I nuclei are significantly less X-ray luminous than the FR-II ones.",

keywords = "Galaxies: active, Galaxies: individual (NGC 315, NGC 4261), X-rays: individual (NGC 315, NGC 4261)",

author = "Yukari Matsumoto and Yasushi Fukazawa and Kazuhiro Nakazawa and Naoko Iyomoto and Kazuo Makishima",

year = "2001",

month = jun,

day = "25",

doi = "10.1093/pasj/53.3.475",

language = "English",

volume = "53",

pages = "475--481",

journal = "Publications of the Astronomical Society of Japan",

issn = "0004-6264",

publisher = "Oxford University Press",

number = "3",

}

TY - JOUR

T1 - The FR-I radio galaxies NGC 315 and NGC 4261 observed with ASCA

AU - Matsumoto, Yukari

AU - Fukazawa, Yasushi

AU - Nakazawa, Kazuhiro

AU - Iyomoto, Naoko

AU - Makishima, Kazuo

PY - 2001/6/25

Y1 - 2001/6/25

N2 - FR-I radio galaxies NGC 315 and NGC 4261 were observed in X-rays with ASCA for ∼ 37 ks and ∼ 54 ks, respectively. Hard X-ray emission from a point-like source at the nucleus was detected at a 2-10 keV luminosity of 3.1 × 1041 and 9.2 × 1040 erg s-1, respectively, for assumed distances of 66 Mpc and 29 Mpc (for H0 = 75 km s-1 Mpc-1). The 2-10 keV spectra of NGC 315 and NGC 4261 were both fitted successfully with a power-law of photon index 2.02 ± 0.34 and 1.45 ± 0.11, respectively, plus emission from hot gas. The NGC 315 nucleus is mildly absorbed. No X-ray variability was detected from either object, with typical upper limits of several tens per cent. These results imply the presence of a low-luminosity active galactic nucleus in both galaxies, and reconfirm the previous recognition that the FR-I nuclei are significantly less X-ray luminous than the FR-II ones.

AB - FR-I radio galaxies NGC 315 and NGC 4261 were observed in X-rays with ASCA for ∼ 37 ks and ∼ 54 ks, respectively. Hard X-ray emission from a point-like source at the nucleus was detected at a 2-10 keV luminosity of 3.1 × 1041 and 9.2 × 1040 erg s-1, respectively, for assumed distances of 66 Mpc and 29 Mpc (for H0 = 75 km s-1 Mpc-1). The 2-10 keV spectra of NGC 315 and NGC 4261 were both fitted successfully with a power-law of photon index 2.02 ± 0.34 and 1.45 ± 0.11, respectively, plus emission from hot gas. The NGC 315 nucleus is mildly absorbed. No X-ray variability was detected from either object, with typical upper limits of several tens per cent. These results imply the presence of a low-luminosity active galactic nucleus in both galaxies, and reconfirm the previous recognition that the FR-I nuclei are significantly less X-ray luminous than the FR-II ones.

KW - Galaxies: active

KW - Galaxies: individual (NGC 315, NGC 4261)

KW - X-rays: individual (NGC 315, NGC 4261)

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UR - https://www.scopus.com/pages/publications/0035948337#tab=citedBy

U2 - 10.1093/pasj/53.3.475

DO - 10.1093/pasj/53.3.475

M3 - Article

AN - SCOPUS:0035948337

SN - 0004-6264

VL - 53

SP - 475

EP - 481

JO - Publications of the Astronomical Society of Japan

JF - Publications of the Astronomical Society of Japan

IS - 3

ER -

The FR-I radio galaxies NGC 315 and NGC 4261 observed with ASCA

Abstract

All Science Journal Classification (ASJC) codes

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