Search Publications
X-ray properties of dust-obscured galaxies with broad optical/UV emission lines
Brandt, William N.; Garmire, Gordon P.; Zou, Fan +4 more
Dust-obscured galaxies (DOGs) with extreme infrared luminosities may represent a key phase in the co-evolution of galaxies and supermassive black holes. We select 12 DOGs at 0.3 ≲ z ≲ 1.0 with broad Mg II or H β emission lines and investigate their X-ray properties utilizing snapshot observations (~3 ks per source) with Chandra. By assuming that t…
An ionized accretion disc wind in Hercules X-1
Fabian, A. C.; Reynolds, C. S.; Pinto, C. +3 more
Hercules X-1 is one of the best-studied highly magnetized neutron star X-ray binaries with a wealth of archival data. We present the discovery of an ionized wind in its X-ray spectrum when the source is in the high state. The wind detection is statistically significant in most of the XMM-Newton observations, with velocities ranging from 200 to 100…
NGTS and WASP photometric recovery of a single-transit candidate from TESS
Hellier, Coel; Jackman, James A. G.; Wheatley, Peter J. +26 more
The Transiting Exoplanet Survey Satellite (TESS) produces a large number of single-transit event candidates, since the mission monitors most stars for only ∼27 d. Such candidates correspond to long-period planets or eclipsing binaries. Using the TESS Sector 1 full-frame images, we identified a 7750 ppm single-transit event with a duration of 7 h a…
Extinction in the 11.2 µm PAH band and the low L11.2/LIR in ULIRGs
Pérez-González, Pablo G.; Arribas, Santiago; Alonso-Herrero, Almudena +9 more
We present a method for recovering the intrinsic (extinction-corrected) luminosity of the 11.2 µm PAH band in galaxy spectra. Using 105 high S/N Spitzer/IRS spectra of star-forming galaxies, we show that the equivalent width ratio of the 12.7 and 11.2 µm PAH bands is independent on the optical depth (τ), with small dispersion (∼5 per c…
Eigengalaxies: describing galaxy morphology using principal components in image space
Kaviraj, Sugata; Geach, James E.; Uzeirbegovic, Emir
We demonstrate how galaxy morphologies can be represented by weighted sums of 'eigengalaxies' and how eigengalaxies can be used in a probabilistic framework to enable principled and simplified approaches in a variety of applications. Eigengalaxies can be derived from a Principal Component Analysis (PCA) of sets of single- or multiband images. They…
Origin of spin-orbit misalignments: the microblazar V4641 Sgr
Salvesen, Greg; Pokawanvit, Supavit
Of the known microquasars, V4641 Sgr boasts the most severe lower limit (>52°) on the misalignment angle between the relativistic jet axis and the binary orbital angular momentum. Assuming the jet and black hole spin axes coincide, we attempt to explain the origin of this extreme spin-orbit misalignment with a natal kick model, whereby an align…
Swift UVOT grism observations of nearby Type Ia supernovae - II. Probing the progenitor metallicity of SNe Ia with ultraviolet spectra
Filippenko, A. V.; Foley, R. J.; Kuin, N. P. M. +2 more
Ultraviolet (UV) observations of Type Ia supernovae (SNe Ia) are crucial for constraining the properties of their progenitor systems. Theoretical studies predicted that the UV spectra, which probe the outermost layers of an SN, should be sensitive to the metal content of the progenitor. Using the largest SN Ia UV (λ < 2900 Å) spectroscopic samp…
Maximum entropy estimation of the Galactic bulge morphology via the VVV Red Clump
Coleman, B.; Paterson, D.; Gordon, C. +2 more
The abundance and narrow magnitude dispersion of Red Clump (RC) stars make them a popular candidate for mapping the morphology of the bulge region of the Milky Way. Using an estimate of the RC's intrinsic luminosity function, we extracted the three-dimensional density distribution of the RC from deep photometric catalogues of the VISTA Variables i…
From peculiar morphologies to Hubble-type spirals: the relation between galaxy dynamics and morphology in star-forming galaxies at z ∼ 1.5
Smail, Ian; Swinbank, A. M.; Fisher, D. B. +14 more
We present an analysis of the gas dynamics of star-forming galaxies at z ∼ 1.5 using data from the KMOS Galaxy Evolution Survey. We quantify the morphology of the galaxies using HSTCANDELS imaging parametrically and non-parametrically. We combine the H α dynamics from KMOS with the high-resolution imaging to derive the relation between stellar mas…
The lively accretion disc in NGC 2992 - I. Transient iron K emission lines in the high-flux state
Bianchi, S.; De Marco, B.; Matt, G. +5 more
We report on one of the brightest flux levels of the Seyfert 2 galaxy NGC 2992 ever observed in X-rays, on 2019 May. The source has been monitored every few days from 2019 March 26 to 2019 December 14 by Swift-X-Ray Telescope (XRT), and simultaneous XMM-Newton (250 ks) and NuSTAR (120 ks) observations were triggered on 2019 May 6. The high count r…