José María Torrelles

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Synchrotron emission is commonly found in relativistic jets from active galactic nuclei (AGNs) and microquasars, but so far its presence in jets from young stellar objects (YSOs) has not been proved. Here, we present evidence of polarized synchrotron emission arising from the jet of a YSO. The apparent magnetic field, with strength of ~0.2 milligauss, is(More)
We report a radio detection of supernova SN 2004ip in the circumnuclear region of the luminous infrared galaxy IRAS 18293-3413, using Very Large Array (VLA) observations at 8.4 GHz on 11 June 2007. SN 2004ip had been previously discovered at near-infrared wavelengths using adaptive optics observations, but its nature (core-collapse or thermonuclear) could(More)
We present linear and circular polarization observations of the H 2 O masers in 4 distinct regions spread over 1 × 2 arcseconds around the HW2 high-mass young stellar object in the Cepheus A star-forming region. We find magnetic fields between 100–500 mG in the central maser region, which has been argued to trace a circumstellar disk. The masers further(More)
We analyze sensitive, high angular resolution (0. 00 3) Very Large Array observations made at 6-cm of the thermal jet Cep A HW2 in two epochs separated by 1.3 years. The subtraction of the maps made at the two epochs clearly shows the presence of brightness enhancements that travel in the jet at a velocity of 950150 km s ?1. We also use these results to(More)
A star like the Sun becomes a planetary nebula towards the end of its life, when the envelope ejected during the earlier giant phase becomes photoionized as the surface of the remnant star reaches a temperature of approximately 30,000 K. The spherical symmetry of the giant phase is lost in the transition to a planetary nebula, when non-spherical shells and(More)
4 RESUMEN Las observaciones interferométricas de la emisión maser de diversas moléculas (p. ABSTRACT Interferometric maser observations of several molecular species (e.g., H 2 O, OH, CH 3 OH) provide a very powerful tool to study with high-angular resolution the molecular gas close to protostars. In this way, groups of maser spots have been found to be(More)
We present radio continuum observations of the planetary nebula (PN) IRAS 17347-3139 (one of the only two known to harbour water maser emission), made to derive its spectral index and the turnover frequency of the emission. The spectrum of the source rises in the whole frequency range sampled, from 2.4 to 24.9 GHz, although the spectral index seems to(More)
The exact processes by which interstellar matter condenses to form young stars are of great interest, in part because they bear on the formation of planets like our own from the material that fails to become part of the star. Theoretical models suggest that ejection of gas during early phases of stellar evolution is a key mechanism for removing excess(More)
The current paradigm of star formation through accretion disks, and magnetohydrodynamically driven gas ejections, predicts the development of collimated outflows, rather than expansion without any preferential direction. We present radio continuum observations of the massive protostar W75N(B)-VLA 2, showing that it is a thermal, collimated ionized wind and(More)
We show preliminary results from a sample of Luminous and Ultra-Luminous Infrared Galaxies (LIRGs and ULIRGs, respectively) in the local universe, obtained from observations using the Very Large Array (VLA), the Multi-Element Radio Link Interferometer Network (MERLIN), and the European VLBI Network (EVN). The main goal of our high-resolution,(More)