English
Related papers

Related papers: Nuclear activity and massive star formation in the…

200 papers

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 detection of a weak X-ray point source coincident with the nucleus of the bulgeless disk galaxy NGC 3621, recently discovered by Spitzer to display high ionization mid-infrared lines typically associated with AGN. These…

High Energy Astrophysical Phenomena · Physics 2009-07-24 M. Gliozzi , S. Satyapal , M. Eracleous , L. Titarchuk , C. C. Cheung

We present results from three nearly simultaneous NuSTAR and Chandra monitoring observations between 2012 Sep 2 and 2012 Nov 16 of local star-forming galaxy NGC 253. The 3-40 keV NuSTAR intensity of the inner 20 arcsec (~400 pc) nuclear…

Chandra observations of the core of the nearby starburst galaxy NGC 253 reveal a heavily absorbed source of hard X-rays embedded within the nuclear starburst region. The source has an unabsorbed, 2 to 10 keV luminosity of >=10^39 erg/s and…

Astrophysics · Physics 2009-11-07 Kimberly Weaver , Timothy Heckman , David Strickland , Michael Dahlem

We present a multi-wavelength study of the active nucleus and the off-nuclear X-ray sources in the nearby spiral galaxy, NGC 1365 using three simultaneous UV/X-ray observations by AstroSat over a two months period and archival IR…

High Energy Astrophysical Phenomena · Physics 2023-02-08 Subhashree Swain , Gulab Chand Dewangan , P. Shalima , Prakash Tripathi , K . V. P. Latha

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

HST UV STIS imaging and spectroscopy of the low luminosity AGN (LLAGN) NGC 4303 have identified the previously detected UV-bright nucleus of this galaxy, as a compact, massive and luminous stellar cluster. The cluster with a size (FWHM) of…

Astrophysics · Physics 2009-11-07 Luis Colina , Rosa Gonzalez Delgado , Miguel Mas-Hess , Claus Leitherer

We present Chandra observations of the enigmatic galaxy IRAS00317-2142, which is classified as a star-forming galaxy on the basis of the ionization level of its emission lines. However, a weak broad H\alpha wing and a high X-ray luminosity…

Astrophysics · Physics 2016-08-30 I. Georgantopoulos , A. Zezas , M. J. Ward

We utilize the complimentary capabilities of XMM-Newton and Chandra, to conduct a detailed imaging and spectral study of the nearby galaxy NGC 4945 focussing on its nucleus and immediate surroundings (within ~1 kpc of the nucleus). A…

Astrophysics · Physics 2016-08-30 N. J. Schurch , T. P. Roberts , R. S. Warwick

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…

High-resolution X-ray observations offer a unique tool for probing the still elusive connection between galaxy mergers and active galactic nuclei (AGNs). We present an analysis of nuclear X-ray emission in an optically selected sample of 92…

Astrophysics of Galaxies · Physics 2023-06-07 Lin He , Meicun Hou , Zhiyuan Li , Shuai Feng , Xin Liu

We present new Chandra X-ray Observatory and Hubble Space Telescope observations of eight optically selected broad-line AGN candidates in nearby dwarf galaxies ($z<0.055$). Including archival Chandra observations of three additional…

High Energy Astrophysical Phenomena · Physics 2017-02-15 Vivienne F. Baldassare , Amy E. Reines , Elena Gallo , Jenny E. Greene

We present the results of a 100 ks {\it Chandra} observation of the NGC 404 nuclear region. The long exposure and excellent spatial resolution of {\it Chandra} has enabled us to critically examine the nuclear environment of NGC 404, which…

We have observed the nearby spiral galaxy NGC6503 using Chandra. Seven discrete sources associated with the galaxy have been found, one of them coincident with its Liner-starburst nucleus. One of the sources corresponds to a ULX with Lx >~…

Astrophysics · Physics 2007-05-23 P. Lira , R. Johnson , A. Lawrence

We present the results of a 17 ks Chandra observation of the nearby dwarf spiral galaxy NGC 4395, focusing on the X-ray properties of the moderate-mass black hole that resides in its nucleus. Chandra affords the first high-quality,…

Astrophysics · Physics 2007-05-23 E. C. Moran , M. Eracleous , K. M. Leighly , G. Chartas , A. V. Filippenko , L. C. Ho , P. R. Blanco

(ABRIDGED) AIMS: We searched for X-ray signatures of AGN in a sample of star-forming, relatively early-type, nearby spiral galaxies. Such galaxies are likely to host nuclear super-massive black holes. METHODS: For 9 sources from the Ho et…

Astrophysics · Physics 2008-11-26 P. Tzanavaris , I. Georgantopoulos

We report Chandra observations of the Scd galaxy NGC 2139, which is known to host a recently formed (10^7.6 yrs) nuclear star cluster. The star cluster is undetected in X-rays, with an upper bound on 0.5-7 keV luminosity of L_X < 7.1 x…

Astrophysics of Galaxies · Physics 2015-06-05 Joseph C. Shields , Torsten Boeker , Luis C. Ho , Hans-Walter Rix , Roeland P. van der Marel , C. Jakob Walcher

NGC 4527 is a nearby edge-on spiral galaxy with both starburst and AGN features, hosting a LINER nucleus. We present a radio study of the large-scale structure and nuclear region of this galaxy, based on new uGMRT observations at 700 and…

Astrophysics of Galaxies · Physics 2025-09-03 C. A. Galante , G. E. Romero , J. Saponara , P. Benaglia

We present Chandra and XMM-Newton observations of the composite star-forming/Seyfert galaxy IRAS20051-1117. The X-ray imaging and spectral properties reveal the presence of an active nucleus. The Chandra image shows a strong nuclear point…

Astrophysics · Physics 2009-11-10 I. Georgantopoulos , I. Papadakis , A. Zezas , M. J. Ward

Obscured active galactic nuclei (AGNs) are thought to be very common in the Universe. Observations and surveys have shown that the number of sources increases for near galaxies and at the low-luminosity regime (the so-called LLAGNs).…

‹ Prev 1 2 3 10 Next ›