Search Publications
Extended hard-X-ray emission in the inner few parsecs of the Galaxy
Hailey, Charles J.; Mori, Kaya; Bauer, Franz E. +19 more
The Galactic Centre hosts a puzzling stellar population in its inner few parsecs, with a high abundance of surprisingly young, relatively massive stars bound within the deep potential well of the central supermassive black hole, Sagittarius A* (ref. 1). Previous studies suggest that the population of objects emitting soft X-rays (less than 10 kilo…
Nested Shells Reveal the Rejuvenation of the Orion-Eridanus Superbubble
Brown, Anthony G. A.; Bally, John; Ochsendorf, Bram B. +1 more
The Orion-Eridanus superbubble is the prototypical superbubble owing to its proximity and evolutionary state. Here we provide a synthesis of recent observational data from WISE and Planck with archival data, allowing us to draw a new and more complete picture on the history and evolution of the Orion-Eridanus region. We discuss the general morphol…
Cosmic Evolution of Black Holes and Spheroids. V. The Relation between Black Hole Mass and Host Galaxy Luminosity for a Sample of 79 Active Galaxies
Treu, Tommaso; Auger, Matthew W.; Malkan, Matthew A. +3 more
We investigate the cosmic evolution of the black hole (BH) mass-bulge luminosity relation using a sample of 52 active galaxies at z ~ 0.36 and z ~ 0.57 in the BH mass range of 107.4-109.1 M ⊙. By consistently applying multicomponent spectral and structural decomposition to high-quality Keck spectra and high-resolut…
Beyond Ellipse(s): Accurately Modelling the Isophotal Structure of Galaxies with ISOFIT and CMODEL
Ciambur, B. C.
This work introduces a new fitting formalism for isophotes that enables more accurate modeling of galaxies with non-elliptical shapes, such as disk galaxies viewed edge-on or galaxies with X-shaped/peanut bulges. Within this scheme, the angular parameter that defines quasi-elliptical isophotes is transformed from the commonly used, but inappropria…
The Brightest Young Star Clusters in NGC 5253.
Schaerer, D.; Östlin, G.; Herrero, A. +43 more
The nearby dwarf starburst galaxy NGC 5253 hosts a number of young, massive star clusters, the two youngest of which are centrally concentrated and surrounded by thermal radio emission (the “radio nebula”). To investigate the role of these clusters in the starburst energetics, we combine new and archival Hubble Space Telescope images of NGC 5253 w…
Geomorphology of the Imhotep region on comet 67P/Churyumov-Gerasimenko from OSIRIS observations
Jorda, L.; Lamy, P. L.; Lara, L. M. +48 more
Context. Since August 2014, the OSIRIS Narrow Angle Camera (NAC) onboard the Rosetta spacecraft has acquired high spatial resolution images of the nucleus of comet 67P/Churyumov-Gerasimenko, down to the decimeter scale. This paper focuses on the Imhotep region, located on the largest lobe of the nucleus, near the equator.
Aims: We map, invent…
Strong C+ Emission in Galaxies at z ~ 1-2: Evidence for Cold Flow Accretion Powered Star Formation in the Early Universe
Spoon, Henrik; Verma, Aprajita; Nikola, Thomas +5 more
We have recently detected the [C II] 157.7 µm line in eight star-forming galaxies at redshifts 1 to 2 using the redshift (z) Early Universe Spectrometer (ZEUS). Our sample targets star formation dominant sources detected in PAH emission. This represents a significant addition to [C II] observations during the epoch of peak star formation. We…
Detecting stars, galaxies, and asteroids with Gaia
de Bruijne, J. H. J.; Hestroffer, D.; Krone-Martins, A. +3 more
Context. Gaia is Europe's space astrometry mission, aiming to make a three-dimensional map of 1000 million stars in our Milky Way to unravel its kinematical, dynamical, and chemical structure and evolution.
Aims: We present a study of Gaia's detection capability of objects, in particular non-saturated stars, double stars, unresolved external …
Iron K and Compton hump reverberation in SWIFT J2127.4+5654 and NGC 1365 revealed by NuSTAR and XMM-Newton
Harrison, F. A.; Stern, D.; Zhang, W. W. +13 more
In the past five years, a flurry of X-ray reverberation lag measurements of accreting supermassive black holes have been made using the XMM-Newton telescope in the 0.3-10 keV energy range. In this work, we use the NuSTAR (Nuclear Spectroscopic Telescope Array) telescope to extend the lag analysis up to higher energies for two Seyfert galaxies, SWI…
IRIS observations of the Mg ii h and k lines during a solar flare
Fletcher, L.; Qiu, J.; Simões, P. J. A. +1 more
The bulk of the radiative output of a solar flare is emitted from the chromosphere, which produces enhancements in the optical and UV continuum, and in many lines, both optically thick and thin. We have, until very recently, lacked observations of two of the strongest of these lines: the Mg ii h and k resonance lines. We present a detailed study o…