Search Publications
Reaching the peak of the quasar spectral energy distribution - I. Observations and models
Done, Chris; Elvis, Martin; McDowell, Jonathan C. +3 more
We perform a spectral analysis of a sample of 11 medium redshift (1.5 ≲ z ≲ 2.2) quasars. Our sample all have optical spectra from the SDSS, infrared spectra from GNIRS and TripleSpec, and X-ray spectra from XMM-Newton. We first analyse the Balmer broad emission line profiles which are shifted into the IR spectra to constrain black hole masses. Th…
Discovery of a quasi-periodic oscillation in the ultraluminous X-ray source IC 342 X-1: XMM-Newton results
Agrawal, V. K.; Nandi, Anuj
We report the discovery of a quasi-periodic oscillation (QPO) at 642 mHz in an XMM-Newton observation of the ultraluminous X-ray source (ULX) IC 342 X-1. The QPO has a centroid at νQPO = 642 ± 20 mHz, a coherence factor Q = 11.6 and an amplitude (rms) of 4.1 per cent with significance of 3.6σ. The energy dependence study shows that the …
Evolution of mid-infrared galaxy luminosity functions from the entire AKARI NEP deep field with new CFHT photometry
Goto, Tomotsugu; Kim, Seong Jin; Burgarella, Denis +22 more
We present infrared (IR) galaxy luminosity functions (LFs) in the AKARI North Ecliptic Pole (NEP) deep field using recently-obtained, wider Canada-France-Hawaii Telescope (CFHT) optical/near-IR images. AKARI has obtained deep images in the mid-infrared (IR), covering 0.6 deg2 of the NEP deep field. However, our previous work was limited…
Do we detect the galactic feedback material in X-ray observations of nearby galaxies? - a case study of NGC 5866
Li, Jiang-Tao
One of the major sources of the X-ray emitting hot gas around galaxies is the feedback from supernovae (SNe), but most of this metal-enriched feedback material is often not directly detected in X-ray observations. This missing galactic feedback problem is extremely prominent in early-type galaxy bulges, where there is little cool gas to make the T…
On the diffuse X-ray emission from the Wolf-Rayet bubble NGC 2359
Gruendl, R. A.; Chu, Y. -H.; Guerrero, M. A. +1 more
A recent XMM-Newton observation has revealed diffuse X-ray emission inside the nebula NGC 2359 around the Wolf-Rayet star WR 7. Taking advantage of an improved point-source rejection and background subtraction, and a detailed comparison of optical and X-ray morphology, we have reanalysed these X-ray observations. Our analysis reveals diffuse X-ray…
The evolution of disc galaxies with and without classical bulges since z ∼ 1
Sachdeva, Sonali; Saha, Kanak; Gadotti, Dimitri A. +1 more
Establishing relative role of internally and externally driven mechanisms responsible for disc and bulge growth is essential to understand the evolution of disc galaxies. In this context, we have studied the physical properties of disc galaxies without classical bulges in comparison to those with classical bulges since z ∼ 0.9. Using images from t…
The X-ray properties of weak-lensing-selected galaxy clusters
Birkinshaw, M.; Maughan, B. J.; Massey, R. +4 more
We present the results of an X-ray follow-up campaign targeting 10 weak-lensing (WL)-selected galaxy clusters from a Subaru WL survey. Archival Chandra data exist for two of the clusters, and we obtain dedicated observations of the remaining eight. The WL clusters appear to fit the same scaling relation between X-ray luminosity and temperature as …
New multiwavelength observations of the Of?p star CPD -28° 2561
Ilyin, I.; Hubrig, S.; Ignace, R. +7 more
A rather strong mean longitudinal magnetic field of the order of a few hundred gauss was detected a few years ago in the Of?p star CPD -28° 2561 using FORS2 (FOcal Reducer low dispersion Spectrograph 2) low-resolution spectropolarimetric observations. In this work, we present additional low-resolution spectropolarimetric observations obtained duri…
A deep look at the nuclear region of UGC 5101 through high angular resolution mid-IR data with GTC/CanariCam
Esquej, P.; Hernán-Caballero, A.; Aretxaga, I. +13 more
We present an analysis of the nuclear infrared (IR, 1.6-18 µm) emission of the ultraluminous IR galaxy UGC 5101 to derive the properties of its active galactic nucleus (AGN) and its obscuring material. We use new mid-IR high angular resolution (0.3-0.5 arcsec) imaging using the Si-2 filter (λC = 8.7 µm) and 7.5-13 µm s…
Detailed afterglow modelling and host galaxy properties of the dark GRB 111215A
Kouveliotou, C.; Wijers, R. A. M. J.; Fynbo, J. P. U. +13 more
Gamma-ray burst (GRB) 111215A was bright at X-ray and radio frequencies, but not detected in the optical or near-infrared (nIR) down to deep limits. We have observed the GRB afterglow with the Westerbork Synthesis Radio Telescope and Arcminute Microkelvin Imager at radio frequencies, with the William Herschel Telescope and Nordic Optical Telescope…