S. Geier

SPECTROSCOPIC CONFIRMATION OF AN ULTRAMASSIVE AND COMPACT GALAXY AT z = 3.35: A DETAILED LOOK AT AN EARLY PROGENITOR OF LOCAL GIANT ELLIPTICALS

We present the first spectroscopic confirmation of an ultramassive galaxy at redshift using data from Keck-NIRSPEC, VLT-X-shooter, and GTC-Osiris. We detect strong [O iii] and Ly? emission, and weak [O ii], C iv, and He ii, placing C1-23152 at a spectroscopic redshift of . The modeling of the emission-line-corrected spectral energy distribution (SED) results in a best-fit stellar mass of , a star formation rate of <7 yr?1, and negligible dust extinction. The stars appear to have formed in a short intense burst ?300?500 Myr prior to the observation epoch, setting the formation redshift of this galaxy at z ? 4.1. From the analysis of the line ratios and widths and the observed flux at 24 ?m, we confirm the presence of a luminous hidden active galactic nucleus (AGN), with bolometric luminosity of erg s?1. Potential contamination of the observed SED from the AGN continuum is constrained, placing a lower limit on the stellar mass of . HST/WFC3 and ACS images are modeled, resulting in an effective radius of kpc in the band and a S?rsic index . This object may be a prototype of the progenitors of local most massive elliptical galaxies in the first 2 Gyr of cosmic history, having formed most of its stars at in a highly dissipative, intense, and short burst of star formation. C1-23152 is completing its transition to a post-starburst phase while hosting a powerful AGN, potentially responsible for the quenching of the star formation activity.

THE EXTENDED HIGH A(V) QUASAR SURVEY: SEARCHING FOR DUSTY ABSORBERS TOWARD MID-INFRARED-SELECTED QUASARS

We present the results of a new spectroscopic survey for dusty intervening absorption systems, particularly damped Ly

GRB 161219B/SN 2016jca: A low-redshift gamma-ray burst supernova powered by radioactive heating

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The High AV Quasar Survey: A z = 2.027 metal-rich damped Lyman-α absorber towards a red quasar at z = 3.21

absorbers (DLAs), towards reddened quasars. The candidate quasars are selected from mid-infrared photometry from the Wide-field Infrared Survey Explorer combined with optical and near-infrared photometry. Out of 1073 candidates, we secure low-resolution spectra for 108 using the Nordic Optical Telescope on La Palma, Spain. Based on the spectra, we are able to classify 100 of the 108 targets as quasars. A large fraction (50 %) is observed to have broad absorption lines (BALs). Moreover, we find 6 quasars with strange breaks in their spectra, which are not consistent with regular dust reddening. Using template fitting we infer the amount of reddening along each line of sight ranging from A(V)

Determining the fraction of reddened quasars in COSMOS with multiple selection techniques from X-ray to radio wavelengths

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SERENDIPITOUS DISCOVERY OF A PROJECTED PAIR OF QSOs SEPARATED BY 4.5 arcsec ON THE SKY

0.1 mag to 1.2 mag (assuming an SMC extinction curve). In four cases, the reddening is consistent with dust exhibiting the 2175A feature caused by an intervening absorber, and for two of these, a MgII absorption system is observed at the best-fit absorption redshift. In the rest of the cases, the reddening is most likely intrinsic to the quasar. We observe no evidence for dusty DLAs in this survey. However, the large fraction of BAL quasars hampers the detection of absorption systems. Out of the 50 non-BAL quasars only 28 have sufficiently high redshift to detect Ly

CIRCE: The Canarias InfraRed Camera Experiment for the Gran Telescopio Canarias

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Unidentified quasars among stationary objects from Gaia DR2

in absorption.

A quasar hiding behind two dusty absorbers: Quantifying the selection bias of metal-rich, damped Lyα absorption systems★

Since the first discovery of a broad-lined type Ic supernova (SN) with a long-duration gamma-ray burst (GRB) in 1998, fewer than fifty GRB-supernovae (SNe) have been discovered. The intermediate-luminosity Swift GRB 161219B and its associated supernova SN 2016jca, which occurred at a redshift of z = 0.1475, represents only the seventh GRB-SN to have been discovered within 1 Gpc, and hence provides an excellent opportunity to investigate the observational and physical properties of these very elusive and rare type of SN. As such, we present optical to near-infrared photometry and optical spectroscopy of GRB 161219B and SN 2016jca, spanning the first three months since its discovery. GRB 161219B exploded in the disk of an edge-on spiral galaxy at a projected distance of 3.4 kpc from the galactic centre. GRB 161219B itself is an outlier in the E p,i − E γ, iso plane, while SN 2016jca had a rest-frame, peak absolute V -band magnitude of M V = − 19.0 ± 0.1, which it reached after 12.3 ± 0.7 rest-frame days. We find that the bolometric properties of SN 2016jca are inconsistent with being powered solely by a magnetar central engine, and demonstrate that it was likely powered exclusively by energy deposited by the radioactive decay of nickel and cobalt into their daughter products, which were nucleosynthesised when its progenitor underwent core collapse. We find that 0.22 ± 0.08 M ⊙ of nickel is required to reproducethe peak luminosity of SN 2016jca, and we constrain an ejecta mass of 5.8 ± 0.3 M ⊙ and a kinetic energy of 5.1 ± 0.8 × 10 52 erg. Finally, we report on a chromatic, pre-maximum bump in the g -band light curve, and discuss its possible origin.

A precise measurement of the magnetic field in the corona of the black hole binary V404 Cygni

To fully exploit the potential of quasars as probes of cosmic chemical evolution and the internal gas dynamics of galaxies it is important to understand the selection effects behind the quasar samples and in particular if the selection criteria exclude foreground galaxies with certain properties (most importantly a high dust content). Here we present spectroscopic follow-up from the 10.4-m GTC telescope of a dust-reddened quasar, eHAQ0111+0641, from the extended High A_V Quasar (HAQ) survey. We find that the z=3.21 quasar has a foreground Damped Lyman-alpha Absorber (DLA) at z=2.027 along the line of sight. The DLA has very strong metal lines due to a moderately high metallicity (with an inferred lower limit of 25% of the solar metallicity), but a very large gas column density along the line-of-sight in its host galaxy. This discovery is further evidence that there is a dust bias affecting the census of metals, caused by the combined effect of dust obscuration and reddening, in existing samples of z>2 DLAs. The case of eHAQ0111+0641 illustrates that dust bias is not only caused by dust obscuration, but also dust reddening.