Search Publications
Soft excess in the quiescent Be/X-ray pulsar RX J0812.4-3114
Ho, Wynn C. G.; Potekhin, Alexander Y.; Heinke, Craig O. +3 more
We report a 72 ks XMM-Newton observation of the Be/X-ray pulsar (BeXRP) RX J0812.4-3114 in quiescence (L_X ≈ 1.6× 10^{33} erg s^{-1}). Intriguingly, we find a two-component spectrum, with a hard power-law (Γ ≈ 1.5) and a soft blackbody-like excess below ≈1 keV. The blackbody component is consistent in kT with a prior quiescent Chandra observation …
Progressive steepening of the SNR RX J1713.7-3946 X-ray spectrum from XMM-Newton to INTEGRAL
Churazov, Eugene; Krivonos, Roman; Kuznetsova, Ekaterina +2 more
In this work, we present the first detailed analysis of the supernova remnant RX J1713.7-3946 in the hard X-ray energy range with the Imager on Board the INTEGRAL Satellite (IBIS) coded-mask telescope onboard the INTEGRAL observatory. The shell-type morphology of the entire remnant is mapped in hard X-rays for the first time and significantly dete…
Gemini IFU, VLA, and HST observations of the OH Megamaser Galaxy IRAS17526 + 3253
Storchi-Bergmann, T.; Robinson, A.; Riffel, R. A. +7 more
We present a multiwavelength study of the OH megamaser galaxy IRAS17526 + 3253, based on new Gemini multi-object spectrograph integral field unit (GMOS/IFU) observations, Hubble Space Telescope F814W, and H α + [N II] images, and archival 2MASS and 1.49 GHz VLA data. The Hubble Space Telescope(HST) images clearly reveal a mid-to-advanced stage maj…
Compact Galaxies at intermediate redshifts quench faster than normal-sized Galaxies
Menéndez-Delmestre, K.; Charbonnier, A.; Gonçalves, T. S. +2 more
Massive quiescent compact galaxies have been discovered at high redshifts, associated with rapid compaction and cessation of star formation (SF). In this work, we set out to quantify the time-scales in which SF is quenched in compact galaxies at intermediate redshifts. For this, we select a sample of green valley galaxies within the COSMOS field i…
Mode of accretion in episodic radio galaxies and the dynamics of their outer relic lobes
Hota, Ananda; Hardcastle, M. J.; Croston, J. H. +3 more
We present X-ray observations with the X-ray Multi-Mirror Mission Newton telescope of three double-double radio galaxies (DDRGs). We have detected the core, lobes, and environment of our sample DDRGs in X-rays. We examine the relationships between the radio and X-ray emission and attribute the X-ray emission from the lobes to the inverse Compton s…
A new possible accretion scenario for ultra-luminous X-ray sources
Makishima, K.; Nakazawa, K.; Kobayashi, Shogo B.
Using archival data from Suzaku, XMM-Newton, and NuSTAR, nine representative ultra-luminous X-ray sources (ULXs) in nearby galaxies were studied. Their X-ray spectra were all reproduced with a multicolour disc emission model plus its Comptonization. However, the spectral shapes of individual sources changed systematically depending on the luminosi…
Evidence for bimodal orbital separations of white dwarf-red dwarf binary stars
Gänsicke, B. T.; Marsh, T. R.; Ashley, R. P. +2 more
We present the results of a radial velocity survey of 20 white dwarf plus M dwarf binaries selected as a follow up to a Hubble Space Telescope study that aimed to spatially resolve suspected binaries. Our candidates are taken from the list of targets that were spatially unresolved with Hubble. We have determined the orbital periods for 16 of these…
The GALANTE photometric system
Lennon, D. J.; García-Lario, P.; Maíz Apellániz, J. +9 more
This paper describes the characterization of the GALANTE photometric system, a seven intermediate- and narrow-band filter system with a wavelength coverage from 3000 Å to 9000 Å. We describe the photometric system presenting the full sensitivity curve as a product of the filter sensitivity, CCD, telescope mirror, and atmospheric transmission curve…
Swift UVOT observations of the 2015 outburst of V404 Cygni
Altamirano, D.; Knigge, C.; Page, M. J. +10 more
The black hole binary, V404 Cygni, went into outburst in 2015 June, after 26 years of X-ray quiescence. We observed the outburst with the Neil Gehrels Swift observatory. We present optical/UV observations taken with the Swift Ultra-violet Optical Telescope, and compare them with the X-ray observations obtained with the Swift X-ray Telescope. We fi…
Early-type galaxies in low-density environments: NGC 6876 explored through its globular cluster system
Bassino, Lilia P.; Caso, Juan P.; Ennis, Ana I. +1 more
We present the results of a photometric study of the early-type galaxy NGC 6876 and the surrounding globular cluster (GC) system. The host galaxy is a massive elliptical, the brightest of this type in the Pavo Group. According to its intrinsic brightness (Mv ∼ -22.7), it is expected to belong to a galaxy cluster instead of a poor group.…