A5084434764- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- History and Developments in Astronomy
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Pulsars and Gravitational Waves Research
- Molecular Spectroscopy and Structure
- Solar and Space Plasma Dynamics
- Adaptive optics and wavefront sensing
- High-pressure geophysics and materials
- SAS software applications and methods
- Astronomical and nuclear sciences
- Geophysics and Gravity Measurements
- Nuclear Physics and Applications
- Spectroscopy and Laser Applications
- Atomic and Molecular Physics
- Particle Detector Development and Performance
- Planetary Science and Exploration
Instituto de Astrofísica de Andalucía
2015-2024
Consejo Superior de Investigaciones Científicas
1999-2014
Universidad Nacional Autónoma de México
2014
Macquarie University
2013
Rochester Institute of Technology
2011
Museum of the American Revolution
2009
University of Illinois Urbana-Champaign
1999-2008
Autonomous University of Sinaloa
2007
Association of Universities For Research In Astronomy
2001-2004
University of Illinois System
1999-2003
This White Paper, submitted to the recent ESA call for science themes define its future large missions, advocates need a transformational leap in our understanding of two key questions astrophysics: 1) How does ordinary matter assemble into scale structures that we see today? 2) do black holes grow and shape Universe? Hot gas clusters, groups intergalactic medium dominates baryonic content local Universe. To understand astrophysical processes responsible formation assembly these structures,...
Context . The source FH Ser experienced a slow classical nova outburst in February 1970 that was the first ever observed at UV, optical, and IR wavelengths. Its remnant is elliptical has multiple knots. A peculiar ring-like filament lies along its minor axis. Aims We investigate here true 3D spatio-kinematical structure of to assess effects early shaping mass kinetic energy. Methods obtained integral field spectroscopic observations made with Very Large Telescope (VLT) VIsible MultiObject...
We report the results from a homogeneous analysis of X-ray (Chandra ACIS) data available for sample 51 LINER galaxies selected catalogue by Carrillo et al. (1999, Rev. Mex. Astron. Astrofis., 35, 187) and representative population bright sources. The nuclear morphology has been classified their compactness in hard band (4.5–8.0 keV) into 2 categories: active galactic nuclei (AGN) candidates (with clearly identified unresolved source) starburst (SB) (without clear source). Sixty percent total...
We present an overview of the initial results from Chandra Planetary Nebula Survey (ChanPlaNS), first systematic (volume-limited) X-ray Observatory survey planetary nebulae (PNe) in solar neighborhood. The phase ChanPlaNS targeted 21 mostly high-excitation PNe within ~1.5 kpc Earth, yielding 4 detections diffuse emission and 9 X-ray-luminous point sources at central stars (CSPNe) these objects. Combining with those obtained archival data for all (14) other that have been observed to date, we...
We report the results of an intense, spectroscopic survey all 41 late-type, nitrogen-rich Wolf–Rayet (WR) stars in Large Magellanic Cloud (LMC) observable with ground-based telescopes. This concludes decade-long effort Montréal Massive Star Group to monitor every known WR star Clouds except for six crowded WNL R136, which will be discussed elsewhere. The focus our was so-called radial velocity (RV) variability order identify short- intermediate-period (P≲ 200 d) binaries among them. Our are...
We have carried out an intensive spectroscopic campaign to search for binaries via periodic radial velocity (RV) variations among all the nitrogen-rich WN Wolf—Rayet (WR) stars in Small Magellanic Cloud (SMC), and WNE Large (LMC). present this first paper results SMC. Along with of Bartzakos et al. on only carbon/oxygen-rich WR star (AB8, WO4+O4), whole population SMC (11 stars) has now been investigated intensively RV variability. also retrieved time-dependent photometric data public domain...
We present X-ray spectral analysis of 20 point-like sources detected in Chandra Planetary Nebula Survey observations 59 planetary nebulae (PNe) the solar neighborhood. Most these detections are associated with luminous central stars within relatively young, compact nebulae. The vast majority X-ray-emitting at PN cores display "hard" (⩾0.5 keV) emission components that unlikely to be due photospheric from hot (CSPN). Instead, we demonstrate well modeled by optically thin thermal plasmas. From...
SBS0335-052E, one of the most metal-poor (Z ~ 3-4% Z$_{\odot}$) HeII-emitter starbursts known in nearby universe, is studied using optical VLT/MUSE spectroscopic and Chandra X-ray observations. We spatially resolved spectral map nebular HeII$\lambda$4686 emission from which we derived for first time total HeII-ionizing energy budget SBS0335-052E. The HeII line indicative a quite hard ionizing spectrum with photon energies > 4 Ryd, observed to be more common at high-z than locally. Our study...
We present the first results of our search for new, extended planetary nebulae (PNe) based on careful, systematic, visual scrutiny imaging data from Isaac Newton Telescope Photometric Hα Survey Northern Galactic plane (IPHAS). The newly uncovered PNe will help to improve census this important population objects that serve as key windows into late-stage evolution low- intermediate-mass stars. They also facilitate study faint end ensemble PN luminosity function. sensitivity and coverage IPHAS...
The identification of the nebula HaTr,5 with shell remnant historic Nova Sco,1437 around low-accretion rate cataclysmic variable 2MASS,J17022815-4306123 has been used in framework hibernation scenario to set an upper limit ≤580 yr on transition time from a nova-like binary dwarf nova. This work is aimed at clarifying nature HaTr,5, which also deemed possible planetary previous works. We obtained intermediate- and high-dispersion long-slit spectra analyzed them conjunction archival optical...
FH Ser experienced a slow classical nova outburst in February 1970 that was the first one observed at UV, optical, and IR wavelengths. Its remnant is elliptical shape, with multiple knots, peculiar ring-like filament along its minor axis. This work aims unveiling true 3D spatio-kinematical structure to investigate effects of early shaping assess mass kinetic energy using VLT VIMOS integral field spectroscopic observations. The data cube has been analyzed visualisations reveal different...
Abstract This work presents the first optical imaging catalogue of resolved Galactic nova remnants. It compiles images from proprietary observations carried out at Nordic Optical Telescope and public archives using different telescopes instruments. The includes spanning 1950 to 2024 66 novae more than 550 detected date. Diffuse emission a shell is in 45 sources, with another 16 sources been stellar five barely resolved. We used introduce main morphological classification remnants (R - round,...
We present in this second paper the results of our intensive spectroscopic campaign to search for binaries via periodic radial-velocity (RV) variations among Wolf—Rayet (WR) stars Large Magellanic Cloud (LMC). observed 61 nitrogen-rich WNE LMC. Along with Bartzakos, Moffat & Niemela on carbon/oxygen-rich WR stars, 2/3 population LMC (134 total) has now been investigated RV variability. have also retrieved time-dependent photometric data public domain from OGLE and MACHO projects, as well...
Planetary Nebulae (PNs) are highly representative of the late stages intermediate mass stellar evolution. However, there still many unresolved questions in their evolutionary scheme. Mass loss processes during Asymptotic Giant Branch (AGB) not fully understood. Binarity, rotation and magnetic fields may play an important role PNs formation. The morphological study will help us to address those questions, therefore a meaningful homogeneous database is needed.
In the context of Instituto de Astrofísica Canarias (IAC) morphological survey Galactic planetary nebulae (PNs), a new class has been found, and we define their members as quadrupolar PNs. We have found five objects whose lobes are, in pairs, symmetric with respect to two different axes. Among these PNs, three (M2-46, K3-24, M1-75) well-defined pairs lobes; another (M3-28 M4-14) are irregular very possibly quadrupolar. For M2-46, measured extension angle between lobes, expansion velocities...
This paper presents a homogeneous study of abundances in sample 79 northern galactic planetary nebulae whose morphological classes have been uniformly determined. Ionic and plasma diagnostics were derived from selected optical line strengths the literature, elemental estimated with Ionization Correction Factor developed by Kingsbourgh & Barlow (1994). We compare to final yields obtained stellar evolution models low-and intermediate-mass stars, we confirm that most Bipolar high nitrogen...
We report on a new Be/X-ray pulsar binary located in the Wing of Small Magellanic Cloud (SMC). The strong pulsed X-ray source was discovered with Chandra and XMM-Newton observatories. pulse period 1062 s is consistently determined from both observations, revealing one slowest rotating pulsars known SMC. optical counterpart emission-line star 2dFS 3831. Its B0-0.5(III)e+ spectral type VLT-FLAMES 2dF spectroscopy, establishing system as (Be-XRB). hard spectrum well fitted by power-law...
We present results from the most recent set of observations obtained as part Chandra X-ray observatory Planetary Nebula Survey (ChanPlaNS), first comprehensive survey planetary nebulae (PNe) in solar neighborhood (i.e., within ~1.5 kpc Sun). The is designed to place constraints on frequency appearance and range spectral characteristics X-ray-emitting PN central stars evolutionary timescales wind-shock-heated bubbles PNe. ChanPlaNS began with a combined Cycle 12 archive 35 continued via 14...
We have obtained Chandra ACIS-S observations of NGC 6543, the Cat's Eye Nebula. The X-ray emission from 6543 is clearly resolved into a point source at central star and diffuse confined within elliptical shell two extensions along major axis. Spectral analysis component shows that abundances X-ray-emitting gas are similar to those fast (1750 km s-1) stellar wind but not nebula. Furthermore, temperature this ~1.7 × 106 K, which 100 times lower than expected postshock wind. combination low...
Recent Chandra ACIS-S observations have detected a point source at the central star of NGC 6543 and confirmed nature hard X-ray emission from 7293. The spectra both sources peak between 0.5 keV 1.0 show line features indicating thin plasma temperatures few times 10^6 K. Their luminosities are 10^30 erg/s 3x10^29 erg/s, respectively. We considered four different mechanisms to explain these sources. may originate coronal activity an undetected companion or shocks in its fast stellar wind,...
Wolf-Rayet (WR) stars are evolved massive with strong fast stellar winds. WR in our Galaxy have shown three possible sources of X-ray emission associated their winds: shocks the winds, colliding and wind-blown bubbles; however, quantitative analyses observations often hampered by uncertainties distances heavy foreground absorption. These problems mitigated Magellanic Clouds (MCs), which at known small internal extinction. We therefore started a survey MCs using archival Chandra, ROSAT,...
The occurrence of stellar wind in central stars planetary nebulae (CSPNe) can be revealed by the presence P Cygni profiles high-excitation lines overimposed on continuum. We have examined entire FUSE archive and merged all useful observations CSPNe to produce highest quality spectra that used assess winds. Furthermore, individual each CSPN been searched for variability profile. found 44 CSPNe, with a clear correlation between line ionization potential star effective temperature. introduce...
The presence of O vi ions can be indicative plasma temperatures a few ×105 K that are expected in heat conduction layers between the hot shocked stellar wind gas at several 106 and cooler (104 K) nebular planetary nebulae (PNe). We have used FUSE observations PNe to search for emission or absorption as diagnostic layer ensure interior gas. Three showing vi, namely IC 418, NGC 2392, 6826, been selected Chandra diffuse X-ray is indeed detected each these PNe. Among three, 2392 has peculiarly...