A5033009567- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- History and Developments in Astronomy
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Advanced optical system design
- Calibration and Measurement Techniques
- Astrophysics and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Atomic and Molecular Physics
- Historical Astronomy and Related Studies
- Astronomical and nuclear sciences
- Scientific Research and Discoveries
- Molecular Spectroscopy and Structure
- Pulsars and Gravitational Waves Research
- Spacecraft and Cryogenic Technologies
- Geophysics and Gravity Measurements
- Railway Engineering and Dynamics
Instituto de Astrofísica de Canarias
2013-2023
Universidad de La Laguna
2011-2023
Gran Telescopio Canarias (Spain)
2016-2023
Rochester Institute of Technology
2011-2014
Consejo Superior de Investigaciones Científicas
1996-2013
Isaac Newton Group
2002-2012
Universidade Federal de Itajubá
2011
Japan External Trade Organization
2011
IAC (United States)
1996-2008
Centre for Astrophysics of the University of Porto
2008
The INT Photometric Halpha Survey of the Northern Galactic Plane (IPHAS) is a 1800 square degrees CCD survey northern Milky Way spanning latitude range -5 < b +5 (degrees) and reaching down to r' ~ 20 (10-sigma). It may increase number known emission line sources by an order magnitude. Representative observations assessment point-source data from IPHAS, now underway, are presented. obtained Wide Field Camera images in narrow-band, Sloan i' broad-band, filters. We simulate IPHAS (r' -...
The VST Photometric Halpha Survey of the Southern Galactic Plane and Bulge (VPHAS+) is surveying southern Milky Way in u, g, r, i at 1 arcsec angular resolution. Its footprint spans latitude range -5 < b +5 all longitudes south celestial equator. Extensions around Centre to latitudes +/-10 bring much Bulge. This ESO public survey, begun on 28th December 2011, reaches down 20th magnitude (10-sigma) will provide single-epoch digital optical photometry for 300 million stars. observing strategy...
The INT/WFC Photometric H-Alpha Survey of the Northern Galactic Plane (IPHAS) is a 1800 square degrees imaging survey covering latitudes |b| < 5 deg and longitudes l = 30 to 215 in r, i H-alpha filters using Wide Field Camera (WFC) on 2.5-metre Isaac Newton Telescope (INT) La Palma. We present first quality-controlled globally-calibrated source catalogue derived from survey, providing single-epoch photometry for 219 million unique sources across 92% footprint. observations were carried out...
We address the general problem of luminosity-specific planetary nebula (PN) number, better known as 'α' ratio, given by α=NPN/Lgal, and its relationship with age metallicity parent stellar population. Our analysis relies on population synthesis models that account for simple populations (SSPs), more elaborate galaxy covering full star formation range different Hubble morphological types. This theoretical framework is compared updated census PN in Local Group (LG) galaxies external...
We present BVRI photometry and optical spectroscopy of two Type Ic supernovae SN 2007bg 2007bi discovered in wide-field, non-targeted surveys associated with sub-luminous blue dwarf galaxies. Neither SNe nor were found association an observed GRB, but are to inhabit similar low-metallicity environments as GRB supernovae. The radio-bright is hosted by extremely galaxy magnitude MB = -12.4+/-0.6 mag estimated oxygen abundance 12+log(O/H) 8.18+/-0.17. lightcurve displays one the fastest...
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...
The Isaac Newton Telescope (INT) Photometric H-Alpha Survey (IPHAS) is a 1800 deg2 survey of the Northern Galactic Plane, reaching down to r′∼ 21. We demonstrate how can be used (1) reliably select classical T Tauri star candidates and (2) constrain mass accretion rates with an estimated relative uncertainty 0.6 dex. IPHAS necessary addition spectroscopic surveys because it allows large uniform samples obtained precise handle on selection effects.
Stars are generally spherical, yet their gaseous envelopes often appear non-spherical when ejected near the end of lives. This quirk is most notable during planetary nebula phase these become ionized. Interactions among stars in a binary system suspected to cause asymmetry. In particular, precessing accretion disk around companion believed launch point-symmetric jets, as seen prototype Fleming 1. Our discovery post common-envelope nucleus 1 confirms that this scenario highly favorable....
It has recently been noted that there seems to be a strong correlation between planetary nebulae with close binary central stars, and highly enhanced recombination line abundances. We present new deep spectra of seven objects known have find the heavy element abundances derived from lines exceed those collisionally excited by factors 5-95, placing several these among most extreme abundance discrepancies. This study nearly doubles number star an discrepancy. A statistical analysis all...
The discrepancy between abundances computed using optical recombination lines (ORLs) and collisionally excited (CELs) is a major unresolved problem in nebular astrophysics. We show here that the largest abundance discrepancies are reached planetary nebulae with close binary central stars. This illustrated by deep spectroscopy of three post common-envelope (CE) star. Abell 46 Ou5 have O++/H+ factors larger than 50, as high 300 inner regions 46. 63 has smaller factor around 10, but still above...
HiPERCAM is a portable, quintuple-beam optical imager that saw first light on the 10.4-m Gran Telescopio Canarias (GTC) in 2018. The instrument uses re-imaging optics and 4 dichroic beamsplitters to record $u_s g_s r_s i_s z_s$ ($320-1060$ nm) images simultaneously its five CCD cameras, each of 3.1 arcmin (diagonal) field view. detectors are frame-transfer devices cooled thermo-electrically 183 K, thereby allowing both long-exposure, deep imaging faint targets, as well high-speed (over 1000...
We present a comprehensive observational study of haloes around planetary nebulae (PNe). Deep Hα+[N ii] and/or [O iii] narrow-band images have been obtained for 35 PNe, and faint extended newly discovered in the following 10 objects: Cn 1-5, IC 2165, 2553, NGC 2792, 2867, 3918, 5979, 6578, PB 4, possibly 1747. New deep also other known or suspected haloes, including huge emission 3242 Sh 2-200. In addition, literature was searched, together with new observations an improved data base...
V838 Mon is marking one of the most mysterious stellar outbursts on record. The spectral energy distribution progenitor resembles an under-luminous F main sequence star (at mag), that erupted into a cool supergiant following complex and multi-maxima lightcurve (peaking at mag). outburst spectrum show BaII, LiI lines several elements, with wide P-Cyg profiles moderate retracing emission in Balmer lines. A light-echo discovered expanding around object helped to constrain distance ( pc),...
Context. We present spectroscopic observations of a sample 72 emission-line objects, including mainly H ii regions, in the spiral galaxy M 33. Spectra were obtained with multi-object, wide field spectrograph AF2/WYFFOS at 4.2 m WHT telescope. Line intensities, extinction, and electron density determined for whole objects.
We investigate and discuss the expansion properties of planetary nebulae by means 1D radiation-hydrodynamics models computed for different initial envelope configurations central star evolutionary tracks. In particular, we study how depends on density gradient circumstellar show that it is possible to derive information very last mass-loss episodes during star's final evolution along off asymptotic giant branch. To facilitate comparison with real objects, have also observable quantities like...
The INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is an imaging survey being carried out in Hα, r′ and i′ filters, with Wide Field Camera (WFC) on 2.5-m Isaac Newton Telescope (INT) to a depth r′= 20 (10σ). aimed at revealing large scale organization Milky Way can be applied identifying range stellar populations within it. Mapping emission line objects enables particular focus young old stages evolution ranging from early T-Tauri stars late planetary nebulae. In this...
IPHASX J194359.5+170901 is a new high-excitation planetary nebula with remarkable characteristics. It consists of knotty ring expanding at speed 28 km s−1, and fast collimated outflow in the form faint lobes caps along direction perpendicular to ring. The expansion polar ∼100 their kinematical age twice as large Time-resolved photometry central star reveals sinusoidal modulation period 1.16 d. This interpreted evidence for binarity star, brightness variations being related orbital motion an...
We present new optical spectra of the nearby, bright, planetary nebula NGC 6778. The has been known to emit strong recombination lines for more than 40 years but this is first detailed study its abundances. Heavy element abundances derived from are found exceed those collisionally excited by a factor ~20 in an integrated spectrum nebula, which among largest abundance discrepancy factors. Spatial analysis shows that strongly, centrally peaked, reaching ~40 close central star. star 6778 be...
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...
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...
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,...