Stella Seitz

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We present a catalogue and atlas of low-resolution spectra of a well defined sample of 341 objects in the FORS Deep Field. All spectra were obtained with the FORS instruments at the ESO VLT with essentially the same spectroscopic setup. The observed extragalactic objects cover the redshift range 0.1 to 5.0. 98 objects are starburst galaxies and QSOs at z >(More)
We measure the star formation rate (SFR) as a function of redshift z up to z ≈ 4.5, based on B, I and (I+B) selected galaxy catalogues from the FORS Deep Field (FDF) and the K-selected catalogue from the GOODS-South field. Distances are computed from spectroscopically calibrated photometric redshifts accurate to ∆z/(z spec + 1) ≤ 0.03 for the FDF and ≤(More)
We re-analyze the M31 microlensing event WeCAPP-GL1/Point-AGAPE-S3 taking into account that stars are not point-like but extended. We show that the finite size of stars can dramatically change the self-lensing event rate and (less dramatically) also the halo lensing event rate, if events are as bright as WeCAPP-GL1. The brightness of the brightest events(More)
Aims. We want to derive bias free, accurate photometric redshifts for those fields of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) Wide Data which are covered in the u * , g ′ , r ′ , i ′ and z ′ filters and are public on January 2008. These are 21, 5 and 11 square degrees in the W1, W3 and W4 fields with photometric data for 1.397.545 (W1),(More)
Using the SPectrometer for Infrared Faint Field Imaging (SPIFFI) on the ESO VLT, we have obtained J, H, and K band integral field spectroscopy of the z = 2.565 luminous submillimeter galaxy SMM J14011+0252. A global spectrum reveals the brighter of this spatially resolved system's two components as an intense starburst that is remarkably old, massive, and(More)
We reformulate the transport equation which determines the size, shape and orientation of innnitesimal light beams in arbitrary spacetimes. The behaviour of such light beams near vertices and conjugate points is investigated, with special attention to the singular behaviour of the optical scalars. We then specialize the general transport equation to the(More)
Gravitational light deeection can distort the images of distant sources by its tidal eeects. The population of faint blue galaxies is at suuciently high redshift so that their images are distorted near foreground clusters, with giant luminous arcs being the most spectacular evidence for this eeect. Much weaker distortions, however, can observationally be(More)
We present a new method for reconstructing two-dimensional mass maps of galaxy clusters from the image distortion of background galaxies. In contrast to most previous approaches , which directly convert locally averaged image ellip-ticities to mass maps (direct methods), our entropy-regularized maximum-likelihood method is an inverse approach. Albeit(More)
We present evidence for a coherent shear signal in a field containing the z = 1.2 radio-source PKS1508−05. Since there were no intervening mass concentrations known before targeting this field, we interpret this signal as due to weak lens-ing by large-scale structure. This result is the outcome of a re-analysis of the observations of Fort et al. (1996) in(More)
Re-ionization of the intergalactic medium occurred in the early Universe at redshift z ≈ 6-11, following the formation of the first generation of stars. Those young galaxies (where the bulk of stars formed) at a cosmic age of less than about 500 million years (z ≲ 10) remain largely unexplored because they are at or beyond the sensitivity limits of existing(More)