Search Publications
Major Galaxy Mergers and the Growth of Supermassive Black Holes in Quasars
Schawinski, Kevin; Natarajan, Priyamvada; Urry, C. Megan +3 more
Despite observed strong correlations between central supermassive black holes (SMBHs) and star formation in galactic nuclei, uncertainties exist in our understanding of their coupling. We present observations of the ratio of heavily obscured to unobscured quasars as a function of cosmic epoch up to z ≅ 3 and show that a simple physical model descr…
The Morphology of Passively Evolving Galaxies at z ~ 2 from Hubble Space Telescope/WFC3 Deep Imaging in the Hubble Ultra Deep Field
Gardner, Jonathan P.; Dickinson, M.; Giavalisco, M. +15 more
We present near-IR images, obtained with the Hubble Space Telescope and the WFC3/IR camera, of six passive and massive galaxies at redshift 1.3 < z < 2.4 (specific star formation rate <10-2 Gyr-1 stellar mass M ~ 1011 M sun), selected from the Great Observatories Origins Deep Survey. These image…
Herschel observations of water vapour in Markarian 231
Veilleux, S.; Sanders, D. B.; Savini, G. +32 more
The Ultra luminous infrared galaxy (ULIRG) Mrk 231 reveals up to seven rotational lines of water (H2O) in emission, including a very high-lying (Eupper = 640 K) line detected at a 4σ level, within the Herschel/SPIRE wavelength range (190 < λ (µm) < 640), whereas PACS observations show one H2O line at 78…
Photometric Study of the Kreutz Comets Observed by SOHO from 1996 to 2005
Hamilton, Douglas P.; A'Hearn, Michael F.; Lamy, Philippe +4 more
We present analysis of the photometry of more than 900 Kreutz comets observed by SOHO from 1996 to 2005. The Kreutz comets have "sungrazing" orbits with q≈ 1-2 R sun, high inclinations (i ≈ 143°), and periods of 500-1000 years. We find that they do not have a bimodal distance of peak brightness as previously reported, but instead peak f…
Water cooling of shocks in protostellar outflows. Herschel-PACS map of L1157
de Graauw, Th.; Liseau, R.; Braine, J. +62 more
Context. The far-IR/sub-mm spectral mapping facility provided by the Herschel-PACS and HIFI instruments has made it possible to obtain, for the first time, images of H2O emission with a spatial resolution comparable to ground based mm/sub-mm observations.
Aims: In the framework of the Water In Star-forming regions with Herschel (WI…
The bright end of the z ~ 7 UV luminosity function from a wide and deep HAWK-I survey
Maiolino, R.; Dickinson, M.; Giavalisco, M. +23 more
Aims: We perform a deep search for galaxies in the redshift range 6.5 ≤ z ≤ 7.5 to measure the evolution of the number density of luminous galaxies in this redshift range and derive useful constraints on the evolution of their luminosity function.
Methods: We present here the second half of an ESO Large Programme, which exploits the uniq…
A Detailed Study of Photometric Redshifts for GOODS-South Galaxies
Dickinson, Mark; Ferguson, Henry C.; Giavalisco, Mauro +10 more
We use the deepest and the most comprehensive photometric data currently available for GOODS-South (GOODS-S) galaxies to measure their photometric redshifts. The photometry includes VLT/VIMOS (U band), HST/ACS (F435W, F606W, F775W, and F850LP bands), VLT/ISAAC (J, H, and Ks bands), and four Spitzer/IRAC channels (3.6, 4.5, 5.8, and 8.0 …
Exploring the Origin and Fate of the Magellanic Stream with Ultraviolet and Optical Absorption
Richter, Philipp; Sembach, Kenneth R.; Savage, Blair D. +3 more
We present an analysis of ionization and metal enrichment in the Magellanic Stream (MS), the nearest gaseous tidal stream, using Hubble Space Telescope/STIS and FUSE ultraviolet spectroscopy of two background active galactic nuclei. The targets are NGC 7469, lying directly behind the MS with log N(H I)MS = 18.63 ± 0.03(stat) ± 0.08(syst…
How was the Hubble sequence 6 Gyr ago?
Flores, H.; Hammer, F.; Puech, M. +3 more
The way galaxies assemble their mass to form the well-defined Hubble sequence is amongst the most debated topic in modern cosmology. One difficulty is to link distant galaxies, which emitted their light several Gyr ago, to those at present epoch. Such a link is affected by the evolution or the transformation of galaxies, as well as by numerous sel…
X-ray reverberation in 1H0707-495 revisited
Turner, T. J.; Reeves, J. N.; Braito, V. +1 more
The narrow-line Seyfert1 galaxy 1H0707-495 has previously been identified as showing time lags between flux variations in the soft-energy (0.3-1keV) and medium-energy (1-4keV) X-ray bands that oscillate between positive and negative values as a function of the frequency of the mode of variation. Here we measure and analyse the lags also between a …