A5020478860- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Molecular Spectroscopy and Structure
- Astronomical Observations and Instrumentation
- Atmospheric Ozone and Climate
- Gamma-ray bursts and supernovae
- Spectroscopy and Laser Applications
- Astrophysical Phenomena and Observations
- Calibration and Measurement Techniques
- Astrophysics and Cosmic Phenomena
- Space Exploration and Technology
- Geophysics and Gravity Measurements
- Atomic and Molecular Physics
- Solar and Space Plasma Dynamics
- Radio Astronomy Observations and Technology
- Advanced Chemical Physics Studies
- Archaeological and Historical Studies
- Archaeological and Geological Studies
- Atmospheric and Environmental Gas Dynamics
- Inorganic Fluorides and Related Compounds
- Superconducting and THz Device Technology
- Ionosphere and magnetosphere dynamics
- Galaxies: Formation, Evolution, Phenomena
Spanish National Observatory
2015-2024
Universidad de Alcalá
2023
Institut de Radioastronomie Millimétrique
2008-2021
Nicolaus Copernicus Astronomical Center
2021
Instituto Geográfico Nacional
2020
Yebes Observatory
1993-2019
Chalmers University of Technology
2019
Centro de Astrobiología
2017
National Observatory
2016
Max Planck Institute for Radio Astronomy
2015
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...
There is a group of binary post-AGB stars that show conspicuous NIR excess, usually assumed to arise from hot dust in very compact possibly rotating disks. These are surrounded by significantly fainter nebulae than the "standard", well studied protoplanetary and planetary (PPNe, PNe). We present high-sensitivity mm-wave observations CO lines 24 objects this type. emission detected most observed sources line profiles emissions probably come disks rotation. derive typical values disk mass...
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 COSAS (CO Survey of late AGB Stars), a project to map and analyze the 12CO J = 1−0 2−1 line emission in representative sample circumstellar envelopes around post-AGB stars. The survey was undertaken with aim investigating small- large-scale morphological kinematical properties molecular environment surrounding stars early phases. For this, combines high sensitivity spatial resolving power IRAM Plateau de Bure interferometer better capability 30 m telescope extended emission....
Spectra, taken with the heterodyne instrument, HIFI, aboard Herschel Space Observatory, of O-rich asymptotic giant branch (AGB) stars which form part guaranteed time key program HIFISTARS are presented. The aim this is to study dynamical structure, mass-loss driving mechanism, and chemistry outflows from AGB as a function chemical composition initial mass. We used HIFI instrument observe nine stars, mainly in H2O high rotational CO lines investigate correlation between line luminosity, ratio...
Context. Asymptotic giant branch (AGB) stars lose their envelopes by means of a stellar wind whose driving mechanism is not understood well. Characterizing the composition and thermal dynamical structure outflow provides constraints that are essential for understanding AGB evolution, including rate mass loss isotopic ratios.
So far, only one rotating disk has been clearly identified and studied in AGB or post-AGB objects (in the Red Rectangle), by means of observations with high spectral spatial resolution. However, disks are thought to play a key role late stellar evolution suspected surround many evolved stars. We aim extend our knowledge on these structures. present interferometric CO J=2-1 emission from nebula surrounding star AC Her, source belonging class that share properties Rectangle show hints...
Our ultimate goal is to probe the nature of collimator outflows in pre-planetary nebula CRL 618. 618 uniquely suited for this purpose owing its multiple, bright, and carefully studied finger-shaped east west nucleus. We compare new Hubble Space Telescope images same filters observed as much 11 yr ago uncover large proper motions surface brightness changes multiple outflows. The expansion age ensemble fingers close 100 yr. find strong variations at fingertips during past decade. Deep IR...
CONTEXT: Asymptotic giant branch (AGB) stars are in one of the latest evolutionary stages low to intermediate-mass stars. Their vigorous mass loss has a significant effect on stellar evolution, and is source heavy elements dust grains for interstellar medium. The mass-loss rate can be well traced by carbon monoxide (CO) line emission. AIMS: We present new Herschel HIFI IRAM 30m telescope CO data sample 53 galactic AGB lines cover fairly large range excitation energy from $J=1\to0$ $J=9\to8$...
We present accurate maps of the CO –1 and 1–0 lines made with Plateau de Bure interferometer gas disk around central star(s) Red Rectangle, a well known protoplanetary nebula. confirm that molecular in this source forms perpendicular to conspicuous axis symmetry optical nebula is rotation. detailed modeling emission extensive discussion accuracy values fitted for different parameters. The outer radius ~ () cm, as function assumed distance D, which thought vary between 380 710 pc. rotation...
During their asymptotic giant branch, evolution low-mass stars lose a significant fraction of mass through an intense wind, enriching the interstellar medium with products nucleosynthesis. We observed nearby oxygen-rich branch star IK Tau using high-resolution HIFI spectrometer onboard Herschel. report on first detection H_2^{16}O and rarer isotopologues H_2^{17}O H_2^{18}O in both ortho para states. deduce total water content (relative to molecular hydrogen) 6.6x10^{-5}, ortho-to-para ratio...
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...
view Abstract Citations (78) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Widespread Water Vapor Emission in Orion Cernicharo, J. ; Gonzalez-Alfonso, E. Alcolea, Bachiller, R. John, D. We have discovered spatially extended emission the 313 - 220 line of water vapor Orion. This is first time that has been found interstellar medium. Many strong narrow features with flux density approx. (1 15) x 103 Jy detected around Ori A-IRc2. These appear...
This paper presents and discusses the final data set of a long-term short-spaced monitoring 21 SiO maser sources, mostly evolved stars, carried out in two lines at 43 GHz with Observatorio Astronómico Nacional 13.7 m telescope Centro de Yebes (Guadalajara, Spain).In most objects, more than 80 spectra per transition over period 11 years have been recorded.The new presented here, previously unpublished, represent nearly 50% total collected project.In addition, availability optical light curves...
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 high-resolution (10) maps of 13CO J = 2-1 in the proto-planetary nebula M1-92, Minkowski's Footprint, obtained with Institut de Radioastronomie Millimétrique (IRAM) interferometer at Plateau Bure. confirm main components found our previous works: a central disklike condensation, bipolar double-shell structure axial outward velocity increasing distance to star, and two opposed features tips where maximal deprojected is attained, ~70 km s-1. The major quality data allows us estimate...
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)...
Aims.We aim to study the structure of nebula around post-AGB, binary star 89 Her. The presence a rotating disk this had been proposed but not yet confirmed by observations.
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...
The evolution of low- and intermediate-mass stars on the asymptotic giant branch (AGB) is mainly controlled by rate at which these lose mass in a stellar wind. Understanding driving mechanism strength winds AGB processes enriching their surfaces with products nucleosynthesis are paramount to constraining predicting chemical galaxies. In previous paper we have constrained structure outflowing envelope W Hya using spectral lines $^{12}$CO molecule. Here broaden this study modelling an...