Search Publications
Transition of an X-ray binary to the hard ultraluminous state in the blue compact dwarf galaxy VII Zw 403
Kaaret, P.; Feng, H.; Brorby, M.
We examine the X-ray spectra of VII Zw 403, a nearby low-metallicity blue compact dwarf (BCD) galaxy. The galaxy has been observed to contain an X-ray source, likely a high-mass X-ray binary (HMXB), with a luminosity of 1.3-23 × 1038 erg s-1 in the 0.3-8 keV energy range. A new Suzaku observation shows a transition to a lumin…
VIMOS mosaic integral-field spectroscopy of the bulge and disc of the early-type galaxy NGC 4697
Covone, G.; Capaccioli, M.; Napolitano, N. R. +5 more
We present an integral-field study of the internal structure, kinematics and stellar population of the almost edge-on, intermediate-luminosity (L★) elliptical galaxy NGC 4697. We build extended two-dimensional (2D) maps of the stellar kinematics and line strengths of the galaxy up to ∼0.7 effective radii (Reff) using a mosaic…
Discovery of a second outbursting hyperluminous X-ray source
Torres, M. A. P.; Heida, M.; Jonker, P. G.
We report on six Chandra and one HST/WFC3 observation of CXO J122518.6+144545, discovered by Jonker et al. (2010) as a candidate hyperluminous X-ray source (HLX), X-ray bright supernova or recoiling supermassive black hole at LX = 2.2 × 1041 erg s-1 (if associated with the galaxy at 182 Mpc). We detect a new outbur…
HST+COS spectra of the double white dwarf CSS 41177 place the secondary inside the pulsational instability strip
Gänsicke, B. T.; Marsh, T. R.; Parsons, S. G. +1 more
We present Hubble Space Telescope + Cosmic Origins Spectrograph (HST+COS) data of the eclipsing double white dwarf binary CSS 41177. Due to the temperature difference between the two white dwarfs, the HST+COS far-ultraviolet data are dominated by the hot, primary white dwarf and allow us to precisely measure its temperature (T1). Using …
Multiple AGN in the crowded field of the compact group SDSS J0959+1259
Bianchi, S.; Vignali, C.; Piconcelli, E. +11 more
We present a multiwavelength study of a newly discovered compact group (CG), SDSS J0959+1259, based data from XMM-Newton, Sloan Digital Sky Survey (SDSS) and the Calar Alto optical imager BUSCA. With a maximum velocity offset of 500 km s-1, a mean redshift of 0.035, and a mean spatial extension of 480 kpc, this CG is exceptional in havi…
Is 4U 0114+65 an eclipsing HMXB?
Paul, Biswajit; Belloni, Tomaso M.; Pradhan, Pragati +2 more
We present the pulsation and spectral characteristics of the High-Mass X-ray Binary (HMXB) 4U 0114+65 during a Suzaku observation covering the part of the orbit that included the previously known low-intensity emission of the source (dip) and the egress from this state. This dip has been interpreted in previous works as an X-ray eclipse. Notably, …
Swift J0525.6+2416 and IGR J04571+4527: two new hard X-ray-selected magnetic cataclysmic variables identified with XMM-Newton
Mukai, K.; Israel, G.; de Martino, D. +4 more
IGR J04571+4527 and Swift J0525.6+2416 are two hard X-ray sources detected in the Swift/BAT and INTEGRAL/IBIS surveys. They were proposed to be magnetic cataclysmic variables of the intermediate polar (IP) type, based on optical spectroscopy. IGR J04571+4527 also showed a 1218 s optical periodicity, suggestive of the rotational period of a white d…
The impact of cosmic variance on simulating weak lensing surveys
Mandelbaum, Rachel; Kannawadi, Arun; Lackner, Claire
Upcoming weak lensing surveys will survey large cosmological volumes to measure the growth of cosmological structure with time and thereby constrain dark energy. One major systematic uncertainty in this process is the calibration of the weak lensing shape distortions, or shears. Most upcoming surveys plan to test several aspects of their shear est…
From radio to TeV: the surprising spectral energy distribution of AP Librae
Fortin, P.; Horan, D.; Giebels, B. +10 more
Following the discovery of high-energy (HE; E > 10 MeV) and very-high-energy (VHE; E > 100 GeV) γ-ray emission from the low-frequency-peaked BL Lac (LBL) object AP Librae, its electromagnetic spectrum is studied over 60 octaves in energy. Contemporaneous data in radio, optical and UV together with the (non-simultaneous) γ-ray data are used t…
A XMM-Newton observation of a sample of four close dwarf spheroidal galaxies
Testa, V.; Nucita, A. A.; De Paolis, F. +2 more
We present the results of the analysis of deep archival XMM-Newton observations towards the dwarf spheroidal galaxies Draco, Leo I, Ursa Major II (UMa II) and Ursa Minor (UMi) in the Milky Way neighbourhood. The X-ray source population is characterized and cross-correlated with available databases to infer their nature. We also investigate if inte…