English
Related papers

Related papers: Detection of Compact Nuclear X-Ray Emission in NGC…

200 papers

NGC 4736 is a nearby Sab spiral galaxy, hosting one of the closest examples of a LINER nucleus. We have utilized recent observations by ROSAT and ASCA to characterise the X-ray properties of this galaxy. Twelve discrete X-ray sources are…

Astrophysics · Physics 2009-10-31 T. P. Roberts , R. S. Warwick , T. Ohashi

We report on the 0.1--100 keV BeppoSAX observations of two nearby LINER galaxies, Sombrero and NGC 4736. Chandra ACIS-S observations supplement this broad-beam spectral study with a high resolution look into the nuclear region, and show a…

Astrophysics · Physics 2009-11-07 S. Pellegrini , G. Fabbiano , F. Fiore , G. Trinchieri , A. Antonelli

We obtained observations of NGC 4639 with ASCA in order to investigate its mildly active Seyfert 1 nucleus at hard X-ray energies. Koratkar et al. (1995) have previously shown that the nucleus is a pointlike source in the ROSAT soft X-ray…

We use X-ray observations of three galaxies hosting LINERs (NGC 404, NGC 4736, NGC 4579) with Chandra to study their power sources. We find very diverse properties within this small group: NGC 404 has an X-ray-faint nucleus with a soft,…

Astrophysics · Physics 2009-11-07 M. Eracleous , J. C. Shields , G. Chartas , E. C. Moran

We found several extranuclear (r >~ 3") X-ray nebulae within 40" (6.3 kpc at 32.5 Mpc) of the nucleus of the Seyfert galaxy NGC 2992. The net X-ray luminosity from the extranuclear sources is ~2-3 E39 erg/s (0.3-8.0 keV). The X-ray core…

The results of a 0.4-10.0 keV ASCA spectral analysis of a sample of low-luminosity AGN (LLAGN; M51, NGC 3147, NGC 4258), low-ionization nuclear emission line regions (LINERs; NGC 3079, NGC 3310, NGC 3998, NGC 4579, NGC 4594) and starburst…

Astrophysics · Physics 2009-10-30 A. Ptak , P. Serlemitsos , T. Yaqoob , R. Mushotzky

We present X-ray (ROSAT), infrared, and radio observations of NGC 4395, which harbors the optically least luminous type 1 Seyfert nucleus discovered thus far. In combination with published optical and ultraviolet spectra, we have used these…

We report preliminary results from an arcsecond-resolution X-ray survey of nearby galaxies using ACIS on board Chandra. The total sample consists of 41 low-luminosity AGNs, including Seyferts, LINERs, and LINER/H II transition objects. In…

We report the discovery of an X-ray source coincident with the nuclear star cluster at the dynamical center of the nearby late-type spiral galaxy NGC 2403. The X-ray luminosity of this source varies from below detection levels, ~1e35 erg/s…

Astrophysics · Physics 2011-02-11 Mihoko Yukita , Douglas A. Swartz , Roberto Soria , Allyn F. Tennant

We present an X-ray spectral and spatial analysis of the composite starburst/Seyfert galaxy NGC 1365. Excellent fits of the ROSAT PSPC spectrum are obtained by combining a soft thermal component with a hard powerlaw. The hard component may…

Astrophysics · Physics 2007-05-23 Stefanie Komossa , Hartmut Schulz

We present an investigation of the X-ray properties of 13 LINERs based on ROSAT all-sky survey and pointed PSPC and HRI observations. Several sources are studied for the first time in X-rays. The X-ray spectra are best described by a…

Astrophysics · Physics 2007-05-23 Stefanie Komossa , Hans Boehringer , John P. Huchra

We report the detection of an absorbed central X-ray source and its strong, rapid variability in NGC4395, the least luminous Seyfert nucleus known. The X-ray source exhibits a number of flares with factors of 3-4 flux changes during a half…

Astrophysics · Physics 2009-09-17 K. Iwasawa , A. C. Fabian , O. Almaini , P. Lira , A. Lawrence , K. Hayashida , H. Inoue

We have examined ROSAT soft X-ray observations of a complete, distance-limited sample of Seyfert and LINER galaxies. X-ray data are available for 46 out of 60 such objects which lie within a hemisphere of radius 18 Mpc. We have constructed…

Astrophysics · Physics 2009-11-06 Eve L. Halderson , Edward C. Moran , Alexei V. Filippenko , Luis C. Ho

We briefly review and extend our discussion of the ROSAT detection of the extraordinarily luminous (>10^{42} erg/s) partly extended (> 30 kpc diameter) X-ray emission from the double-nucleus ultraluminous infrared galaxy NGC 6240. The ROSAT…

Astrophysics · Physics 2007-05-23 Hartmut Schulz , Stefanie Komossa , Jochen Greiner

We analyse the ROSAT PSPC spectrum of 19 X-ray selected Narrow Emission Line Galaxies (NELGs) discovered during the optical identification of sources in the ROSAT UK Deep Survey. Their properties are compared to those of broad line Active…

(Abridged) Based on UV to X-ray and radio to UV flux ratios, some argue that low ionization emission line regions (LINERs) and low luminosity AGN (LLAGN) are a scaled-down version of their more luminous predecessors Seyfert galaxies.…

Astrophysics of Galaxies · Physics 2015-05-18 G. Younes , D. Porquet , B. Sabra , N. Grosso , J. N. Reeves , M. G. Allen

NGC 1365 is a Seyfert 2 galaxy with a starburst ring in its nuclear region. In this work we look at the XMM Reflection Grating Spectrometer (RGS) data from four 2012-13, three 2007 and two 2004 observations of NGC 1365. We characterise the…

High Energy Astrophysical Phenomena · Physics 2016-11-03 M. Whewell , G. Branduardi-Raymont , M. J. Page

We report X-ray fluxes in the 2--10 keV band from LINERs (low-ionization nuclear emission-line regions) and low-luminosity Seyfert galaxies obtained with the ASCA satellite. Observed X-ray luminosities are in the range between 4e39 and 5e41…

Astrophysics · Physics 2009-10-31 Yuichi Terashima , Luis C. Ho , Andrew F. Ptak

The nearby barred spiral galaxy NGC 1672 is thought to have a weak Seyfert nucleus in addition to its strong starburst activity. Observations with the PSPC and HRI instruments on board the ROSAT X-ray satellite show that three X-ray sources…

Astrophysics · Physics 2015-06-24 W. N. Brandt , J. P. Halpern , K. Iwasawa

Low luminosity active galactic nuclei are more abundant and closer to us than the luminous ones but harder to explore as they are faint. We have selected the four sources NGC 315, NGC 4261, NGC 1275, and NGC 4486, which have been detected…

High Energy Astrophysical Phenomena · Physics 2021-10-13 Gunjan Tomar , Nayantara Gupta , Raj Prince
‹ Prev 1 2 3 10 Next ›