94 citations · 525 across the 19 of their papers we have counts for
14 papers · 1 filter
Detection of the high z GRB 080913 and its implications on progenitors and energy extraction mechanisms
D. Perez-Ramirez, A. de Ugarte Postigo, J. Gorosabel +15
Aims: We present multiwavelength observations of one of the most distant gamma-ray bursts detected so far, GRB 080913. Based on these observations, we consider whether it could be…
Optical and infrared flares from a transient Galactic soft gamma-ray repeater
A. J. Castro-Tirado, A. de Ugarte Postigo, J. Gorosabel +33
Soft gamma-ray repeaters (SGRs) are a rare type of gamma-ray transient sources that are ocasionally detected as bursts in the high-energy sky. They are thought to be produced by ma…
HCN(1-0) enhancement in the bar of NGC 2903
S. Leon, S. Jeyakumar, D. Perez-Ramirez +3
We have mapped the \hcn emission from two spiral galaxies, NGC2903 and NGC3504 to study the gas properties in the bars. The HCN(1-0) emission is detected in the center and along th…
The night-sky at the Calar Alto Observatory
S. F. Sanchez, J. Aceituno, U. Thiele +2
We present a characterization of the main properties of the night-sky at the Calar Alto observatory for the time period between 2004 and 2007. We use optical spectrophotometric dat…
The dark nature of GRB 051022 and its host galaxy
A. J. Castro-Tirado, M. Bremer, S. McBreen +17
We present multiwavelength (X-ray/optical/near-infrared/millimetre) observations of GRB 051022 between 2.5 hours and ~1.15 yr after the event. It is the most intense gamma-ray burs…
Extensive multiband study of the X-ray rich GRB 050408. A likely off-axis event with an intense energy injection
A de Ugarte Postigo, T. A. Fatkhullin, G. Johannesson +40
Aims. Understand the shape and implications of the multiband light curve of GRB 050408, an X-ray rich (XRR) burst. Methods. We present a multiband optical light curve, covering the…
Chandra X-ray counterpart of KS 1741-293
J. Marti, J. A. Combi, D. Perez-Ramirez +4
We aim to investigate the nature of the high energy source KS 1741-293 by revisiting the radio and infrared associations proposed in the early 1990s. Our work is mostly based on th…
A catalogue of ULX coincidences with FIRST radio sources
J. R. Sanchez-Sutil, A. J. Munoz-Arjonilla, J. Marti +3
We search for ultra luminous X-ray source (ULXs) radio counterparts located in nearby galaxies in order to constrain their physical nature. Our work is based on a systematic cross-…
A radio and infrared exploration of the Cygnus X-3 environments
J. Marti, D. Perez-Ramirez, P. Luque-Escamilla +4
To confirm, or rule out, the possible hot spot nature of two previously detected radio sources in the vicinity of the Cygnus X-3 microquasar. We present the results of a radio and…
The Calar Alto lunar occultation program: update and new results
A. Richichi, O. Fors, M. Merino +6
We present an update of the lunar occultation program which is routinely carried out in the near-IR at the Calar Alto Observatory. A total of 350 events were recorded since our las…
Possible hot spots excited by the relativistic jets of Cygnus X-3
J. Marti, D. Perez-Ramirez, J. L. Garrido +2
We present the results of a deep search for associated radio features in the vicinity of the microquasar Cygnus X-3. The motivation behind is to find out evidence for interaction b…
Circumnuclear regions in barred spiral galaxies II. Relations to host galaxies
J. H. Knapen, D. Perez-Ramirez, S. Laine
We present optical broad- and narrow-band imaging of a sample of a dozen barred galaxies. These images are analyzed in conjunction with our previously published near-infrared imagi…
Circumnuclear kinematics in NGC 5248: the origin of nuclear spiral arms
S. Laine, J. H. Knapen, D. Perez-Ramirez +2
We present for the first time a two-dimensional velocity field of the central region of the grand-design spiral galaxy NGC 5248, at 0.9 arcsec spatial resolution. The H-alpha veloc…
Circumnuclear regions in barred spiral galaxies. I. Near-infrared imaging
D. Perez-Ramirez, J. H. Knapen, R. F. Peletier +3
We present sub-arcsecond resolution ground-based near-infrared images of the central regions of a sample of twelve barred galaxies with circumnuclear star formation activity, which…