A5030535360- 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
- History and Developments in Astronomy
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Adaptive optics and wavefront sensing
- Galaxies: Formation, Evolution, Phenomena
- Scientific Research and Discoveries
- Solar and Space Plasma Dynamics
- Spectroscopy and Laser Applications
- Space Exploration and Technology
- Statistical and numerical algorithms
- Crystallization and Solubility Studies
- Atmospheric Ozone and Climate
- Planetary Science and Exploration
- Molecular Spectroscopy and Structure
- Astrophysics and Cosmic Phenomena
- X-ray Diffraction in Crystallography
- GNSS positioning and interference
- Atomic and Molecular Physics
- Historical Astronomy and Related Studies
Tecnológico de Monterrey
2024
Universidad Nacional Autónoma de México
2009-2022
Ensenada Institute of Technology
1998-2022
Universitat Jaume I
2001-2019
Universidad Autónoma de Baja California
1987-2017
Yebes Observatory
2017
Northeastern University
2016
Rochester Institute of Technology
2011
Instituto de Geofísica y Astronomía
2006
University of Manchester
1983-2005
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...
This paper explores the effects of post-asymptotic giant branch (AGB) winds driven solely by magnetic pressure from stellar surface. It is found that can reach high speeds under this assumption and lead to formation highly collimated proto-planetary nebulae. Bipolar knotty jets with periodic features constant velocity are well reproduced models. Several wind models terminal velocities a few tens km s-1 up 103 calculated, yielding outflows linear momenta in range 1036-1040 g cm s-1, kinetic...
Spatially resolved, long-slit, echelle observations have been obtained in the light of Hα and [N II] λ6548 emission lines for symmetric strings ionized knots emerging from body elliptical planetary nebula Fleming 1. It is found that magnitudes radial velocity differences both systematically increase away nebular center. The north string redshifted, whereas south blue-shifted. difference tip to 148 km s -1 . data are reasonably consistent with a simple ballistic model assumes episodic...
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...
After a hot white dwarf ceases its nuclear burning, helium may briefly and explosively reignite. This causes the star to evolve back into cool giant, whereupon it experiences renewed mass ejection before reheating. A reignition event of this kind was observed in 1996 V4334 Sgr (Sakurai's object). Its temperature decrease 100 times predicted rate. To understand unexpectedly fast evolution, we have developed model which convective mixing is strongly suppressed under influence flash burning....
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...
A spectacular (14' × 4') bipolar nebula, with a symmetric and rotating, high-velocity collimated outflow, episodic outburst properties, has been discovered in the Cassiopeia-Cepheus region. compact object classified as planetary nebula KjPn 8 is located at center of symmetry this extraordinary nebula. The angular extent structure now largest one known associated (PN). mosaic Hα images covering full presented, well [N II] λ6584, [S λ6724, [O λ3729, III] λ5007 central (5' 5') These reveal...
This work presents three-dimensional, magnetohydrodynamic simulations of the formation and early evolution a subgroup planetary nebulae that exhibit variety point-symmetric structures. For bipolar nebulae, nebular shapes along inner borders their opposing lobes, and/or collimated outflows or jets internal external to cavities, is reproduced by considering steady misalignment magnetic collimation axis with respect symmetry wind outflow, defined perpendicular equatorial density enhancement....
Spatially resolved profiles of the Hα, [N II] 6584 Å, and [O III] 5007 Å lines have been obtained with Manchester echelle spectrometer combined 2.1 m San Pedro Mártir telescope over planetary nebula NGC 2440. The resulting position-velocity (PV) arrays are compared ground-based HST archival imagery, revealing complex structure that prevails in this object. This work represents first detailed kinematical study
A deep, continuum-subtracted, image of NGC 7293 has been obtained in the light Halpha+[N II] emission lines. New images two filamentary halo stuctures have and possible detection a collimated outflow made. Spatially resolved, longslit profiles lines observed across several these features with MES combined SPM 2.1m telescope; are compared [N II]6584, [O III]5007, HeII 6560 Halpha over nebular core. The central is originating ~0.34pc diameter spherical volume expanding at <=12km/s which...
We present the first detailed spatiokinematical analysis and modelling of planetary nebula Abell 41, which is known to contain well-studied close-binary system MT Ser. This object represents an important test case in study evolution nebulae with binary central stars as current evolutionary theories predict that plane should be aligned perpendicular symmetry axis nebula. Deep narrow-band imaging light [N ii] 6584 Å, [O iii] 5007 Å [S 6717+6731 obtained using ACAM on William Herschel...
The 3-D and kinematic structure of the Eskimo nebula, NGC 2392, has been notoriously difficult to interpret in detail given its complex morphology, multiple components nearly pole-on orientation along line sight. We present a comprehensive, spatially resolved, high resolution, long-slit spectroscopic mapping planetary nebula. data consist 21 echelle spectra tightly spaced over bipolar jets. This set allows us construct velocity-resolved [NII] channel map nebula with resolution 10 km/s that...
This is the first of a series investigations into far-IR characteristics 11 planetary nebulae (PNs) under Herschel Space Observatory Open Time 1 program, Planetary Nebula Survey (HerPlaNS). Using HerPlaNS data set, we look PN energetics and variations physical conditions within target nebulae. In present work, provide an overview survey, acquisition processing, resulting products. We perform (1) PACS/SPIRE broadband imaging to determine spatial distribution cold dust component in PNs (2)...
A number of planetary nebulae (PNs) exhibit collimated, high-velocity outflows or jets. These hydrodynamical structures cannot be easily accommodated within the classical models evolution post-asymptotic giant branch stars, and understanding them has become a topical problem in PN research. One way to explain existence jets PNs been invoke presence accretion disks, which would presumably set conditions for collimation driving outflows. This work investigates detail type binary systems that...
We present the first detailed kinematical analysis of planetary nebula Abell 63, which is known to contain eclipsing close-binary nucleus UU Sge. 63 provides an important test case in investigating role central stars on evolution nebulae. Longslit observations were obtained using Manchester echelle spectrometer combined with 2.1-m San Pedro Martir Telescope. The spectra reveal that bright rim has a tube-like structure. A deep image shows collimated lobes extending from nebula, are shown be...
The outflowing proper motions of 15 knots in the dominant northwestern lobe high-excitation poly-polar planetary nebula NGC 6302 have been determined by comparing their positions relative to those faint stars an image taken at San Pedro Martir Observatory 2007 a South African Astronomical archival plate obtained Evans 1956. Hubble-type expansion this is now directly confirmed model-independent way from these measurements. Furthermore, unambigous distance 1.17 ± 0.14 kpc determined. Also, all...
We explore the formation of multipolar structures in planetary and pre-planetary nebulae from interaction a fast post-AGB wind with highly inhomogeneous filamentary shell structure assumed to form during final phase high density wind. The simulations were performed new hydrodynamics code integrated interactive framework astrophysical modeling package SHAPE. In contrast conventional software, does not require any programming intervention by user for setting up or controlling code....
High spectral resolution observations of the [N II] 6548 + 6584 Å and Hα emission lines from young planetary nebula MyCn 18 have been obtained using Manchester echelle spectrometer combined with Anglo-Australian Telescope. These spatially resolved spectra reveal not only kinematical characteristics two bright rings emission, which define well-known "engraved hourglass" structure this object, but also dramatic motions faint, irregular knots observed outside main nebular structure. The are...
The Hubble Space Telescope (HST) has revealed the existence of multiple, regularly spaced, and faint concentric shells around some planetary nebulae. Here we present two- (and a half) dimensional magnetohydrodynamic numerical simulations effects solar-like magnetic cycle, with periodic polarity inversions, in slow wind an asymptotic giant branch (AGB) star. stellar is modeled steady mass-loss at constant velocity. This simple version without variations, able to reproduce many properties...
We have obtained Hubble Space Telescope (HST) Imaging Spectrometer high-resolution spectra of the Orion proplyd LV 2 in C III doublet at 1906.68 and 1908.73 Å. New images 6 cm wavelength with MERLIN complement earlier HST a similar spatial resolution. This object is one closest proplyds to θ1 Ori C, source photoionizing photoevaporating radiation. Combining detailed theoretical models has allowed determination mass-loss rate as 8.2 × 10-7 M☉ yr-1 ±10%. mass loss used address conundrum...
NGC 6337 is a member of the rare group planetary nebulae where close binary nucleus has been identified. The nebula's morphology and emission line profiles are both unusual, particularly latter. We present thorough mapping spatially resolved, long-slit echelle spectra obtained over nebula that allows detailed characterization its complex kinematics. This information, together with narrowband imagery, used to produce three-dimensional (3D) model using code SHAPE. 3D yields slowly expanding...
LoTr 1 is a planetary nebula thought to contain an intermediate-period binary central star system (that is, with orbital period, P, between 100 and, say, 1500 days). The shows the signature of K-type, rapidly rotating giant, and most likely constitutes accretion-induced post-mass transfer similar other PNe such as 5, WeBo A70. Such systems represent rare opportunities further investigation into formation barium stars intermediate period post-AGB -- process still far from being understood....
We present high-dispersion spectroscopic data of the compact planetary nebula Vy 1-2, where high expansion velocities up to 100 km/s are found in Ha, [N II] and [O III] emission lines. HST images reveal a bipolar structure. 1-2 displays bright ring-like structure with size 2.4"x3.2" two faint lobes west-east direction. A pair knots is also found, located almost symmetrically on opposite sides at PA=305 degrees. Furthermore, deep low-dispersion spectra presented several lines detected for...