A5057744347- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Molecular Spectroscopy and Structure
- History and Developments in Astronomy
- Atmospheric Ozone and Climate
- Space Exploration and Technology
- Astrophysics and Cosmic Phenomena
- Isotope Analysis in Ecology
- Historical Astronomy and Related Studies
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- High-pressure geophysics and materials
- Literacy and Educational Practices
- Tribology and Lubrication Engineering
- Ancient Egypt and Archaeology
- Planetary Science and Exploration
- Electrophoretic Deposition in Materials Science
- Magnetic Properties of Alloys
Universidad de Sonora
2016-2021
University of Buenos Aires
2019
Universidad Nacional Autónoma de México
2004-2014
Center for Astrophysics Harvard & Smithsonian
2002-2009
Universidad de Morelia
2002
We present multiband photometry of 185 type-Ia supernovae (SNe Ia), with over 11,500 observations. These were acquired between 2001 and 2008 at the F. L. Whipple Observatory Harvard-Smithsonian Center for Astrophysics (CfA). This sample contains largest number homogeneously observed reduced nearby SNe Ia (z ≲ 0.08) published to date. It more than doubles sample, bringing SN cosmology point where systematic uncertainties dominate. Our natural system has a precision ≲0.02 mag in BVRIr'i' ≲0.04...
As part of a systematic search programme 10-degree wide strip the Northern Galactic plane we present preliminary evidence for discovery four (and possibly five) new supernova remnants (SNRs). The pilot area covered 19-20 hour right ascension zone sampling from +20 to +55 degrees in declination using binned mosaic images INT Photometric H-alpha Survey (IPHAS). optical identification candidate SNRs was based mainly on their filamentary and arc-like emission morphologies, apparently coherent,...
We present a spectroscopic survey of the stellar population Sigma Orionis cluster. have obtained spectral types for 340 stars. Spectroscopic data typing come from several spectrographs with similar coverage and resolution. More than half stars our sample are members confirmed by presence lithium in absorption, strong H$\alpha$ emission or weak gravity-sensitive features. In addition, we high resolution (R~34000) spectra region 169 region. Radial velocities were calculated this set. The...
We present results from optical spectra for intermediate-mass stars in the young cluster Trumpler 37. The spectroscopy presented helps to refine membership, reddening (AV ∼ 1.5 ± 0.5), and distance modulus [(m - M) = 9.7 0.2] this cluster. Only three new emission-line were found our sample, resulting a total of four with emission lines spectral type earlier than G. One these stars, LkHα 349, is probably not member central cluster, since it lies within dark globule on periphery H II region IC...
We present accurate optical and radio astrometry for the unresolved contact binary system Cyg OB2 No. 5 its weaker component to northeast. While positions of primary (taken be binary) agree within observational error (~70 mas), we find that does not in position with second system, but falls between two components. conclude this is associated secondary star appears synchrotron emission produced at shock interaction zone winds stars. Differential B- V-band CCD Hipparcos photometry was used...
view Abstract Citations (49) References (40) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS VLA Observations of Massive Stars at 7 Millimeters Contreras, M. E. ; Rodriguez, L. F. Gomez, Y. Velazquez, A. Early-type stars possess ionized winds that produce detectable free-free emission in the radio band. Measurement this thermal radiation was expected to provide a way determine stellar mass-loss rate. However, observations have shown these often strong,...
We have carried out continuum and line polarisation observations of two Proto-planetary nebulae (PPNe), CRL 618 OH 231.8+4.2, using the Submillimeter Array (SMA) in its compact configuration. The frequency range observations, 330-345 GHz, includes CO(J=3-2) emission. 231.8+4.2 show quadrupolar bipolar optical lobes, respectively, surrounded by a dusty envelope reminiscent their AGB phase. report detection dust polarised emission both PPNe above 4 sigma but no molecular 3 limit. is slightly...
We report sensitive, high angular resolution VLA 3.6 cm and 7 mm continuum observations toward the star-forming region Cepheus A. Three embedded young stellar objects (YSOs) were found within a projected area of ≃06 × 06 (400 400 AU2). One sources is already known radio jet HW2 (detected at mm), while other two weak not previously known. these new detected only located ≃015 south from HW2. The source, cm, nearly coincides with center enigmatic expanding bubble water masers recently Very Long...
Aims.We analyse the point-symmetric planetary nebula NGC 6309 in terms of its three-dimensional structure and internal variations physical conditions to deduce processes involved formation.
Wolf-Rayet stars are losing mass via their strong winds. Some of them show thermal and nonthermal radio emission, from this group, some have companions that forming binary systems. It has been suggested the synchrotron emission arises interaction region where winds two collide. WR 147 seems to be one these systems, having a companion emitting as well radiation. Besides, it an anisotropic wind. In work, we present VLA observations provide new information on system. The main component (WR...
We present narrow-band [O III]lambda5007 and H-alpha images, as well long-slit high-resolution echelle spectra of the planetary nebula NGC 6058. Our data reveal that 6058 is a multipolar about ~45 arcsec in extent formed by four bipolar outflows are oriented at different position angles. Assuming homologous expansion for all structures, distance 3.5 kpc, we obtain polar velocities around ~68 km s^-1 three them. The estimated kinematical ages suggest oldest have been ejected intervals ~ 1100...
We present an observational study of the planetary nebula (PN) NGC 7354 consisting narrowband Hα and [N ii]λ6584 imaging as well low- high-dispersion long-slit spectroscopy, VLA-D radio continuum. According to our spectroscopic data, has four main structures: a quite round outer shell elliptical inner shell, collection low-excitation bright knots roughly concentrated on equatorial region nebula, two asymmetrical jet-like features, not aligned either with shells' axes, or each other. have...
The classical model for free-free emission from ionized stellar winds is based on the assumption of a stationary, isotropic and homogeneous wind. However, since there exist objects whose wind behaviour deviates standard model, during last decade these assumptions have been questioned. In this work, we present results 3 bright sources: P Cyg, Cyg OB2 No.12 WR 147. These reported to possess that deviate basic assumptions. We obtained flux densities, sizes, spectral indices mass loss rates each...
Abstract We present an observational study of three oint-ymmetric lanetary ebulae (PS-PNe): PC 19, He 2-429, and 1-1, whose kinematics has been previously reported in the literature. The includes analysis physical conditions chemical abundances. found that abundances 2-429 1-1 correspond to a Peimbert Type I PNe while those 19 are good agreement with IV PN. Kinematic evidence derived from proper motion measurement support classification suggest progenitor star was low-mass low-metallicity...