Search Publications
Ultraviolet and X-ray variability of NGC 4051 over 45 days with XMM-Newton and Swift
Vaughan, S.; Uttley, P.; Alston, W. N.
We analyse 15 XMM-Newton observations of the Seyfert galaxy NGC 4051 obtained over 45 d to determine the ultraviolet (UV) light curve variability characteristics and search for correlated UV/X-ray emission. The UV light curve shows variability on all time-scales, however with lower fractional rms than the 0.2-10 keV X-rays. On days-weeks time-scal…
A high molecular fraction in a subdamped absorber at z = 0.56
Prochaska, J. Xavier; Tejos, Nicolas; Bechtold, Jill +8 more
Measuring rest-frame ultraviolet rotational transitions from the Lyman and Werner bands in absorption against a bright background continuum is one of the few ways to directly measure molecular hydrogen (H2). Here, we report the detection of absorption from H2 at z = 0.56 in a subdamped Lyα system with neutral hydrogen column …
A multiwavelength study of the Magellanic-type galaxy NGC 4449 - I. Modelling the spectral energy distribution, the ionization structure and the star formation history
Cooray, A.; Page, M. J.; Lebouteiller, V. +16 more
We present an integrated photometric spectral energy distribution (SED) of the Magellanic-type galaxy NGC 4449 from the far-ultraviolet (UV) to the submillimetre, including new observations acquired by the Herschel Space Observatory. We include integrated UV photometry from the Swift Ultraviolet and Optical Telescope using a measurement technique …
SHARDS: stellar populations and star formation histories of a mass-selected sample of 0.65 < z < 1.1 galaxies
Barro, Guillermo; Pérez-González, Pablo G.; Tresse, Laurence +10 more
We report on results from the analysis of a stellar mass-selected (log (M*/M⊙) ≥ 9.0) sample of 1644 galaxies at 0.65 < z < 1.1 with ultradeep (mAB < 26.5) optical medium-band (R ∼ 50) photometry from the Survey for High-z Absorption Red and Dead Sources (SHARDS). The spectral resolution of SHARDS allows u…
Quasi-periodic oscillations and energy spectra from the two brightest Ultra-Luminous X-ray sources in M82
Belloni, T.; Zampieri, L.; Caballero-García, M. D.
Ultra-Luminous X-ray sources (ULXs) are thought to be accreting black holes (BHs) that might host intermediate-mass black holes (IMBH), proposed to exist by theoretical studies, even though a firm detection (as a class) is still missing. The brightest ULX in M82 (M82 X-1) is probably one of the best candidates to host an IMBH. In this work, we ana…
Deep hard X-ray survey of the Large Magellanic Cloud
Tsygankov, S. S.; Lutovinov, A. A.; Grebenev, S. A. +1 more
Results of the deep survey of the Large Magellanic Cloud (LMC) obtained with the INTEGRAL observatory are presented. The long exposure ( ∼ 7 Ms) allowed us to detect 21 sources in this sky region: ten belonging to the LMC itself (7 HMXBs, 2 PSRs, 1 LMXB), six of extragalactic origin and three belonging to other galaxies in the Local Group - the Mi…
The NGC 3341 minor merger: a panchromatic view of the active galactic nucleus in a dwarf companion
Fiore, Fabrizio; Mathur, Smita; Bianchi, Stefano +4 more
We present X-ray (Chandra), radio (Expanded Very Large Array and European VLBI Network) and archival optical data of the triple-merging system in NGC 3341. Our panchromatic analysis confirms the presence of a Seyfert 2 active galactic nucleus (AGN) in NGC 3341B, one of the secondary dwarf companions. On the other hand, the nucleus of the primary g…
Supernovae and radio transients in M82
Smartt, S. J.; Fraser, M.; Romero-Cañizales, C. +4 more
We present optical and near-infrared (NIR) photometry and NIR spectroscopy of SN 2004am, the only optically detected supernova (SN) in M82. These demonstrate that SN 2004am was a highly reddened Type II-P SN similar to the low-luminosity Type II-P events such as SNe 1997D and 2005cs. We show that SN 2004am was located coincident with the obscured …
Discovery of a 6.4 h black hole binary in NGC 4490
Sidoli, L.; Esposito, P.; Motta, S. E. +3 more
We report on the discovery with Chandra of a strong modulation (∼90 per cent pulsed fraction) at ∼6.4 h from the source CXOU J123030.3+413853 in the star-forming, low-metallicity spiral galaxy NGC 4490, which is interacting with the irregular companion NGC 4485. This modulation, confirmed also by XMM-Newton observations, is interpreted as the orbi…
The build-up of nuclear stellar cusps in extreme starburst galaxies and major mergers
Sanders, D. B.; Surace, J. A.; Inami, H. +15 more
Nuclear stellar cusps are defined as central excess light component in the stellar light profiles of galaxies and are suggested to be stellar relics of intense compact starbursts in the central ∼100-500 pc region of gas-rich major mergers. Here, we probe the build-up of nuclear cusps during the actual starburst phase for a complete sample of lumin…