English
Related papers

Related papers: The Elusive Active Nucleus of NGC 4945

200 papers

NGC 4945 harbors one of the nearest active galactic nuclei (AGN), which allows reaching high spatial resolution with the current observational facilities. The Seyfert 2 nucleus is deeply obscured by an edge-on disk with $A_V\sim14$,…

The nearly edge-on galaxy NGC4945 is one of the closest galaxies where an AGN and starburst coexist, and is one of the brightest sources at 100 keV. Near and mid-infrared spectroscopy have shown very strong obscuration of its central…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 J. P. Pérez-Beaupuits , H. W. W. Spoon , M. Spaans , J. D. Smith

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 have observed the central region of the nearby starburst galaxy NGC4945 with the mid-infrared spectrometers SWS and PHT-S aboard ISO. We do not find any evidence for the existence of the powerful AGN, inferred from hard X-ray…

Astrophysics · Physics 2007-05-23 H. W. W. Spoon , J. Koornneef , A. F. M. Moorwood , D. Lutz , A. G. G. M. Tielens

NGC 4945 is a nearby (3.8 Mpc) galaxy hosting a nuclear starburst and Seyfert Type 2 AGN. We use the Atacama Large Millimeter/submillimeter Array (ALMA) to image the 93 GHz (3.2 mm) free-free continuum and hydrogen recombination line…

NGC 4945 contains a well-known heavily obscured active galactic nucleus (AGN) at its core, with prior reports of strong nuclear and off-nuclear neutral Fe K$\alpha$ emission due to the AGN activity. We report the discovery of very extended…

We present the analysis of an optical data cube of the central region of NGC 1448, obtained with the Multi Unit Spectroscopic Explorer (MUSE). Chandra X-ray data indicate that the active galactic nucleus (AGN) is not located at the apparent…

Astrophysics of Galaxies · Physics 2021-03-29 R. B. Menezes , Patrícia da Silva , J. E. Steiner

We report on a powerful and variable off-nuclear X-ray source in the nearby spiral galaxy NGC 4945. Two ROSAT PSPC observations show the source to brighten in 0.5--2.0 keV flux by a factor of about 9 on a time-scale of 11 months or less. It…

Astrophysics · Physics 2016-06-08 W. N. Brandt , K. Iwasawa , C. S. Reynolds

We present the results of a BeppoSAX observation of the nearby spiral galaxy NGC4945 in the 0.1-200 keV energy band. The nuclear X-ray emission emerges above ~7 keV, through an absorber with column density N_H ~ a few 10^24/cm/cm. Its…

Astrophysics · Physics 2009-09-25 M. Guainazzi , G. Matt , W. N. Brandt , L. A. Antonelli , P. Barr , L. Bassani

HATLAS J084933.4+021443 was identified as a dusty starburst via its rest-frame far-IR emission. Multi-frequency imaging and spectroscopy revealed a cluster of four dusty galaxies at $z = 2.41$, covering 80 kpc. Here, we use ALMA to confirm…

Astrophysics of Galaxies · Physics 2019-09-04 R. J. Ivison , M. J. Page , M. Cirasuolo , C. M. Harrison , V. Mainieri , V. Arumugam , U. Dudzeviciute

A multi-line millimeter-wave study of the nearby starburst galaxy NGC 4945 has been carried out using the Swedish-ESO Submillimeter Telescope (SEST). The study covers the frequency range from 82 GHz to 354 GHz and includes 80 transitions of…

Astrophysics · Physics 2009-11-10 M. Wang , C. Henkel , Y. -N. Chin , J. Whiteoak , M. Cunningham , R. Mauersberger , D. Muders

Observations of the Seyfert 2 and starburst galaxy NGC 5135 with the Chandra X-ray Observatory demonstrate that both of these phenomena contribute significantly to its X-ray emission. We spatially isolate the active galactic nucleus (AGN)…

Astrophysics · Physics 2016-08-30 N. A. Levenson , K. A. Weaver , T. M. Heckman , H. Awaki , Y. Terashima

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

The discovery over the last several decades of moderate luminosity AGNs in disk-dominated galaxies - which show no "classical" bulges - suggests that secular mechanisms represent an important growth pathway for supermassive black holes in…

The aim of this study is to constrain the dynamics, structure and feeding of the compact nucleous of NGC4418, and to reveal the nature of the main hidden power source: starburst or AGN. We obtained high spatial resolution observations of…

Astrophysics of Galaxies · Physics 2015-06-16 F. Costagliola , S. Aalto , K. Sakamoto , S. Martín , R. Beswick , S. Muller , H. -R. Klöckner

Type 2 active galactic nuclei (AGN) show signatures of accretion onto a supermassive black hole through strong, high-ionization, narrow emission lines extended on scales of 100s to 1000s of parsecs, but they lack the broad emission lines…

High Energy Astrophysical Phenomena · Physics 2022-09-21 M. Lynne Saade , Murray Brightman , Daniel Stern , Matthew A. Malkan , Javier A. Garcia

Suzaku observed a nearby Seyfert 2 galaxy NGC4945, which hosts one of the brightest active galactic nuclei above 20 keV. Combining data from the X-ray CCD camera (XIS) and the Hard X-ray Detector (HXD), the AGN intrinsic nuclear emission…

High quality infrared spectra of active galaxies including the stellar absorption features of Si at 1.59 um, CO(6,3) at 1.62 um, and CO(2,0) at 2.29 um are used to measure the stellar mass to light ratio at 1.65 um (M_H/L) and investigate…

Astrophysics · Physics 2007-05-23 E. Oliva , L. Origlia , R. Maiolino , A. F. M. Moorwood

We have mapped the central region of NGC 4945 in the $J=2\to1$ transition of $^{12}$CO, $^{13}$CO, and C$^{18}$O, as well as the continuum at 1.3 mm, at an angular resolution of $5\farc \times 3\farc$ with the Submillimeter Array. The…

We analyze recent simultaneous Chandra/RXTE observations of the Seyfert 2 galaxy NGC 4945. The unprecedented spatial resolution of Chandra means we are able to separate the spectra of the nucleus, starburst and superwind regions, while the…

Astrophysics · Physics 2009-11-07 Chris Done , Greg M. Madejski , Piotr T. Zycki , Lincoln J. Greenhill
‹ Prev 1 2 3 10 Next ›