A5003447219- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Molecular Spectroscopy and Structure
- Atmospheric Ozone and Climate
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Solar and Space Plasma Dynamics
- Space Exploration and Technology
- Galaxies: Formation, Evolution, Phenomena
- Adaptive optics and wavefront sensing
- Planetary Science and Exploration
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Magnetic Properties and Applications
- Magnetic properties of thin films
- Advanced Combustion Engine Technologies
- Laser-induced spectroscopy and plasma
- Methane Hydrates and Related Phenomena
- Calibration and Measurement Techniques
- Geophysics and Gravity Measurements
- Astrophysics and Cosmic Phenomena
- Phase Equilibria and Thermodynamics
Centro de Astrobiología
2016-2025
Universidad Complutense de Madrid
2001-2018
Instituto de Física Fundamental
2018
National Institute of Astrophysics, Optics and Electronics
2018
Instituto de Estructura de la Materia
2006-2017
Spanish National Observatory
1999-2017
Max Planck Society
2015
Max Planck Institute for Radio Astronomy
2015
Consejo Superior de Investigaciones Científicas
2010-2014
Instituto Nacional de Técnica Aeroespacial
2012
We have studied the CO emission from protoplanetary nebulae (PPNe). Our sample is composed of 37 objects and includes, we think, all well identified PPNe detected in CO, together with two yellow hypergiants emitting one young PN. present a summary existing data, including accurate new observations 12CO 13CO -0 -1 lines 16 objects. identify slowly expanding shell (represented spectra by central core) fast outflow (corresponding to line wings), that known be bipolar. Excluding poor end up 32...
Using the Hubble Space Telescope (HST), we have carried out a survey of candidate preplanetary nebulae (PPNs). We report here our discoveries objects having well-resolved geometric structures, and use large sample PPNs now imaged with HST (including previously studied in this class) to devise comprehensive morphological classification system for category objects. The wide variety aspherical morphologies which found are qualitatively similar those young planetary (PNs) previous surveys. also...
We carried out a millimeter wavelength line survey between 79 and 356 GHz with the IRAM-30m telescope to investigate physical chemical properties of molecular envelope oxygen-rich AGB star IK Tau. analysed lines detected using population diagram technique derive rotational temperatures column densities. Additionally, we conducted radiative transfer analysis SO$_2$ detected. For first time in this source ground vibrational state HCO$^+$, NS, NO, H$_2$CO, as well several isotopologues...
We present the first results of a high-spectral-resolution survey carbon-rich evolved star IRC+10216 that was carried out with HIFI spectrometer onboard <i>Herschel<i/>. This covers all bands, spectral range from 488 to 1901 GHz. In this letter we focus on band-1b spectrum, in 554.5–636.5 GHz, where identified 130 features intensities above 0.03 K and signal-to-noise ratio <i>><i/>5. Detected lines arise HCN, SiO, SiS, CS, CO, metal-bearing species and, surprisingly, silicon dicarbide...
Low- and intermediate-mass stars evolve through the asymptotic giant branch (AGB), when an efficient mass-loss process removes a significant fraction of their initial mass. A substantial increase in rate at end AGB is observed for least some unknown reasons. This creates post-AGB objects that are completely enshrouded thick dusty envelopes might be associated with binary interactions. We $J=2-1$ line $^{13}$CO, C$^{17}$O, C$^{18}$O Atacama Large Millimeter / submillimeter Array (ALMA)...
Low- and intermediate-mass stars evolve through the asymptotic giant branch (AGB) when an efficient mass-loss process removes a significant fraction of their initial mass. For most sources, this relies on interplay between convection, stellar pulsations, dust formation. However, predicting history given star from first principles is complex not yet feasible at present. At end AGB, least some experience substantial increase in rate for unknown reasons, leading to creation post-AGB objects...
Abstract Using optical time series with Telescopi Joan Oró (TJO), Gaia, TESS, and NEOWISE archival data, we performed a variability study on the candidate bloated massive young stellar object (MYSO) IRAS 19520+2759. This is first that star has been tested for theoretically predicted periodic variability. The source found to be variable at mid-infrared wavelengths classified as long-period MYSO. observed TJO data gives period of ∼ 270±40 days (in Rc band) 270±50 Ic band), which very close...
We present the results from analysis of optical spectra 31 Halpha-selected regions in extended UV (XUV) disks M83 (NGC5236) and NGC4625 recently discovered by GALEX. The were obtained using IMACS at Las Campanas Observatory 6.5m Magellan I telescope COSMIC Palomar 200-inch telescope, respectively for NGC4625. line ratios measured indicate nebular oxygen abundances (derived R23 parameter) order Zsun/5-Zsun/10. For most emission-line analyzed fluxes are best reproduced models photoionization...
We aim to study equatorial disks in rotation and axial outflows post-AGB objects, as disclose the formation shaping mechanisms planetary nebulae. So far, both had not been observed simultaneously. have obtained high-quality ALMA observations of 12CO 13CO J=3-2 J=6-5 line emission Red Rectangle, only post-AGB/protoplanetary object which a disk has mapped up date. These provide an unprecedented description complex structure this source. Together with rotation, we find low-velocity outflow that...
In order to study the effects of rotating disks in post-asymptotic giant branch (post-AGB) evolution, we observe a class binary post-AGB stars that seem be systematically surrounded by equatorial and slow outflows. Although dynamics had only been well identified three cases, such structures is thought fundamental understanding formation various phases late evolution ejection planetary nebulae from evolved stars.We present ALMA maps 12CO 13CO J=3-2 lines source IRAS 08544-4431, which belongs...
We present new high-quality ALMA observations of the Red Rectangle (a well known post-AGB object) in C17O J=6-5 and H13CN J=4-3 line emission results from a reduction already published 13CO J=3-2 data. A detailed model fitting all molecular data, including previous maps single-dish spectra, was performed using sophisticated code. These corresponding modeling allowed us to deepen analysis nebular properties. also stress uncertainties fitting. confirm presence rotating equatorial disk an...
We present high spatial resolution observations of the CO molecular emission ( and lines) in post-AGB bipolar nebula OH 231.8+4.2. High-quality NIR images (J, H, K' bands) light scattered by grains were also obtained. Our probe bulk nebular material, providing maps with a ~1´´ mass distribution, both being very closely coincident. The combination two 12CO lines has been used to measure distribution kinetic temperature nebula, which is found be low, ranging between 8 K, outer southern clumps,...
We present 1'' resolution interferometric maps of the CO J = 2-1 and HC3N 25-24 emission in protoplanetary nebula CRL 618 obtained with millimeter array Owens Valley Radio Observatory (OVRO). Our data trace high accuracy spatio-kinematic structure different molecular components: (1) fast, bipolar outflow, which is observed up to axial distances ±25 (±2.7 × 1016 cm) from center a maximal deprojected expansion velocity Vexp ~ 340 km s-1; (2) roughly round outer halo, slowly expanding at 17 (3)...
The search for binarity in AGB stars is of critical importance our understanding how planetary nebulae acquire the dazzling variety aspherical shapes which characterizes this class. However, detecting binary companions such has been severely hampered due to their extreme luminosities and pulsations. We have carried out a small imaging survey ultraviolet light (using GALEX), where these cool objects are very faint, order hotter companions. report discovery significant far-ultraviolet excesses...
We have performed interferometric observations of the 12CO (J = 1–0) emission in a sample 27 objects spanning different evolutionary stages from late asymptotic giant branch (late-AGB), through post-AGB (pAGB) phase, and to planetary nebula (PN) stage, but dominated by pAGB young PNs (⩾81%). In this paper (the first series) we present our maps main nebular properties derived for whole sample. Observations were with Caltech Millimeter Array at Owens Valley Radio Observatory. The angular...
We aim to study the presence of both rotation and expansion in post-AGB nebulae, particular around IW Car, a binary star that was suspected be surrounded by Keplerian disk. obtained high-quality ALMA observations 12CO 13CO J=3-2 lines Car. The maps were analyzed means simplified model CO emission, based on those used for similar objects. Our clearly show gas components rotation, an equatorial disk, expansion, which shows hourglass-like structure with symmetry axis perpendicular plane is...
OH 231.8+4.2, a bipolar outflow around Mira-type variable star, displays unique molecular richness amongst circumstellar envelopes (CSEs) O-rich AGB and post-AGB stars. We report line observations of the HCO+ H13CO+ ions first detection SO+, N2H+, (tentatively) H3O+ in this source. SO+ have not been detected before CSEs evolved These data obtained as part full mm-wave far-IR spectral survey carried out with IRAM 30 m radio telescope Herschel/HIFI. Except for H3O+, all work display emission...
We present low spectral resolution molecular interferometric observations at 1.2 mm obtained with the Combined Array for Research in Millimetre-wave Astronomy (CARMA) towards C-rich AGB star IRC+10216. have mapped emission of several lines SiS, H13CN, SiO and SiC2 ground first excited vibrational states a high angular 0.25 arcsec. These allowed us to partially resolve envelope distances from ≲50 stellar radii (R⋆), where wind is mainly accelerated. The structure has been modelled 3D...
We present high-resolution images obtained with the WFPC2, on board HST, of protoplanetary nebula (PPN) OH 231.8+4.2. Hα and NII line emission scattered light in continuum at 6750 7910 Å were observed. also discuss NIR NICMOS from HST archive. The show high accuracy shape excitation state shocks developed nebula. Our (and data other works) allow a very detailed quantitative description different nebular components physical conditions them. interpret specific structures identified our using...
We report high angular resolution (~1'') CO J = 3-2 interferometric mapping using the Submillimeter Array (SMA) of IRAS 22036+5306 (I22036), a bipolar preplanetary nebula (PPN) with knotty jets discovered in our HST snapshot survey young PPNs. In addition, we have obtained supporting lower (~10'') and 13CO 1-0 observations Owens Valley Radio Observatory (OVRO) interferometer, as well optical long-slit echelle spectra at Palomar Observatory. The show presence very fast (~220 km s-1), highly...
We present echelle long-slit optical spectra of a sample objects evolving off the AGB, most them in pre-planetary nebula (pPN) phase, obtained with ESI and MIKE spectrographs at Keck-II Magellan-I, respectively. The total wavelength range covered (MIKE) is ~3900 to 10900 A (~3600 7200A). In this paper, we focus our analysis mainly on Halpha profiles. Prominent emission detected half objects, which show broad wings (up ~4000 km/s). majority Halpha-emission sources, fast, post-AGB winds are...
OH231.8+4.2 is a well studied O-rich CSE around an intermediate-mass evolved star that displays bipolar molecular outflows accelerated up to 400 km/s. OH231 also presents exceptional richness probably due shock-induced chemical processes. We report the first detection in this source of HNCO, HNCS, HC3N and NO, with IRAM-30m telescope sensitive mm-wavelength survey towards target. HNCO HNCS are detections CSEs. The observed line profiles show emission arises massive central component envelope...
We present continuum and molecular line emission ALMA observations of OH 231.8+4.2, a well studied bipolar nebula around an asymptotic giant branch (AGB) star. The high angular resolution (~0.2-0.3 arcsec) sensitivity our maps provide the most detailed accurate description overall nebular structure kinematics this object to date. have identified number outflow components previously unknown. Species in work include 12CO, 13CO, CS, SO, SO2, OCS, SiO, SiS, H3O+, Na37Cl, CH3OH. molecules Na37Cl...