Search Publications
Almost gone: SN 2008S and NGC 300 2008OT-1 are fainter than their progenitors
Kochanek, C. S.; Stanek, K. Z.; Shappee, B. J. +3 more
We present late-time Hubble and Spitzer Space Telescope (SST) imaging of SN 2008S and NGC 300 2008OT-1, the prototypes of a common class of stellar transients whose true nature is debated. Both objects are still fading and are now >15 times fainter than their progenitors in the mid-IR and are undetected in the optical and near-IR. Data from the…
The 2016 Feb 19 outburst of comet 67P/CG: an ESA Rosetta multi-instrument study
Jorda, L.; Lamy, P. L.; Stern, S. A. +93 more
On 2016 Feb 19, nine Rosetta instruments serendipitously observed an outburst of gas and dust from the nucleus of comet 67P/Churyumov-Gerasimenko. Among these instruments were cameras and spectrometers ranging from UV over visible to microwave wavelengths, in situ gas, dust and plasma instruments, and one dust collector. At 09:40 a dust cloud deve…
The dust-scattering component of X-ray extinction: effects on continuum fitting and high-resolution absorption edge structure
García, J.; Wilms, J.; Baganoff, F. +1 more
Small angle scattering by dust grains causes a significant contribution to the total interstellar extinction for any X-ray instrument with sub-arcminute resolution (Chandra, Swift, XMM-Newton). However, the dust-scattering component is not included in the current absorption models: phabs, TBabs, and TBnew. We simulate a large number of Chandra spe…
Quantifying the UV-continuum slopes of galaxies to z ∼ 10 using deep Hubble+Spitzer/IRAC observations
Wilkins, Stephen M.; Labbé, Ivo; Bouwens, Rychard J. +5 more
Measurements of the UV-continuum slopes β provide valuable information on the physical properties of galaxies forming in the early universe, probing the dust reddening, age, metal content, and even the escape fraction. While constraints on these slopes generally become more challenging at higher redshifts as the UV-continuum shifts out of the Hubb…
SKA weak lensing - I. Cosmological forecasts and the power of radio-optical cross-correlations
Zuntz, Joe; Camera, Stefano; Brown, Michael L. +1 more
We construct forecasts for cosmological parameter constraints from weak gravitational lensing surveys involving the Square Kilometre Array (SKA). Considering matter content, dark energy and modified gravity parameters, we show that the first phase of the SKA (SKA1) can be competitive with other Stage III experiments such as the Dark Energy Survey …
First identification of direct collapse black hole candidates in the early Universe in CANDELS/GOODS-S
Grazian, Andrea; Ferrara, Andrea; Fiore, Fabrizio +3 more
The first black hole seeds, formed when the Universe was younger than ∼500 Myr, are recognized to play an important role for the growth of early (z ∼ 7) supermassive black holes. While progresses have been made in understanding their formation and growth, their observational signatures remain largely unexplored. As a result, no detection of such s…
A comprehensive analysis of the hard X-ray spectra of bright Seyfert galaxies
Papadakis, I. E.; Paltani, S.; Walter, R. +7 more
Hard X-ray spectra of 28 bright Seyfert galaxies observed with INTEGRAL were analysed together with the X-ray spectra from XMM-Newton, Suzaku and RXTE. These broad-band data were fitted with a model assuming a thermal Comptonization as a primary continuum component. We tested several model options through a fitting of the Comptonized continuum acc…
Non-linearity and environmental dependence of the star-forming galaxies main sequence
Finoguenov, A.; Berta, S.; Magnelli, B. +30 more
Using data from four deep fields (COSMOS, AEGIS, ECDFS, and CDFN), we study the correlation between the position of galaxies in the star formation rate (SFR) versus stellar mass plane and local environment at z < 1.1. To accurately estimate the galaxy SFR, we use the deepest available Spitzer/MIPS 24 and Herschel/PACS data sets. We distinguish …
Unexpected and significant findings in comet 67P/Churyumov-Gerasimenko: an interdisciplinary view
Fulchignoni, M.; Grün, E.; Altobelli, N. +5 more
ESA's Rosetta Mission has followed Comet 67P/Churyumov-Gerasimenko from 3.6 au inbound to 3.6 au outbound. Many results are largely unexpected, as compared to previous models based on in situ and ground-based observations of Jupiter-family comets. The main topics discussed in this review are (1) the importance of the large concavities characterizi…
Detection of the first infra-red quasi-periodic oscillation in a black hole X-ray binary
van der Klis, M.; Casella, P.; Maccarone, T. +5 more
We present the analysis of fast variability of Very Large Telescope/ISAAC (Infrared Spectrometer And Array Camera) (infra-red), XMM-Newton/OM (optical) and EPIC-pn (X-ray), and RXTE/PCA (X-ray) observations of the black hole X-ray binary GX 339-4 in a rising hard state of its outburst in 2010. We report the first detection of a quasi-periodic osci…