![Izquierda - Imagen RGB de la nebulosa de Orión y M43 obtenida filtros estrechos con la cámara WFC en el INT: H alfa (rojo), [S II] 6716+30 (verde), [O III] 5007 (azul). Derecha - Imagen en falso color de la nebulosa planetaria NGC 6778. En azul se ve la emisión en la línea de O II tomada con el filtro sintonizable azul del instrumento OSIRIS en el GTC; en verde imagen con el filtro estrecho de [O III] del Nordic Optical Telescope (NOT).](https://webpro-cms.ll.iac.es/sites/default/files/styles/color/public/images/project/imagen_web.jpg?itok=mgPK3oTc "Izquierda - Imagen RGB de la nebulosa de Orión y M43 obtenida filtros estrechos con la cámara WFC en el INT: H alfa (rojo), [S II] 6716+30 (verde), [O III] 5007 (azul). Derecha - Imagen en falso color de la nebulosa planetaria NGC 6778. En azul se ve la emisión en la línea de O II tomada con el filtro sintonizable azul del instrumento OSIRIS en el GTC; en verde imagen con el filtro estrecho de [O III] del Nordic Optical Telescope (NOT).")
Start year
1986
Organizational Unit
Organizing institutions
General
Description
The research that is being carried out by the group can be condensed into two main lines:
1) Study of the structure, dynamics, physical conditions and chemical evolution of Galactic and extragalactic ionized nebulae through detailed analysis and modelization of their spectra. Investigation of chemical composition gradients along the disk of our Galaxy and in nearby galaxies.
2) Determine the physical-chemical conditions of galactic planetary nebulae with bipolar geometry and nebulae around symbiotic stars. The aim is to understand the origin of bipolarity and to test theoretical models that attempt to explain nebular morphology and kinematics, with special emphasis on models with central binary stars. We will also study the implications of the evolution of binary systems in other astrophysical scenarios, such as the formation of jets, cataclysmic variables, and nova and supernova-type explosions.
Members
Principal investigator
Jorge
García Rojas
Project manager
César
Esteban López
Project staff
David
Jones
Antonio
Mampaso Recio
Collaborators
Dr.
Miguel Cerviño Saavedra
Dr.
A.R. López Sánchez
Dr.
F. Bresolin
Dr.
G. Delgado Inglada
Dr.
G. Domínguez Guzmán
Dr.
X. Fang
Dr.
N.C. Sterling
Dr.
R. Wesson
Dr.
H. Monteiro
Dr.
H. Boffin
Dra.
Karla Z. Arellano Córdoba
Dr.
M. Miller Bertolami
Dra.
Grazyna Stasinska
Dr.
T. Hillwig
Dr.
B. Miszalski
Dr.
M. Santander García
Dra.
E. Villaver
Dra.
L. Magrini
Dr.
S. Akras
Prof.
J. Drew
Prof.
B. Balick
Dr.
D. R. Gonçalves
Dra.
K. Kwitter
Dr.
A. Prsa
Results
- Using EMIR/GTC spectra in the near infrared range, tellurium and bromine emission lines have been detected for the first time in two planetary nebulae. These heavy element detections in one of their places where they are formed, give us information about the abundance patterns of heavy elements owing to the r-process and the s-process.
Scientific activity
Related publications
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Detection of a large Be circumstellar disk during X-ray quiescence of XTE J1946+274Aims: We present a multiwavelength study of the Be/X-ray binary system XTE J1946+274 with the main goal of better characterizing its behavior during X-ray quiescence. We also aim to shed light on the possible mechanisms which trigger the X-ray activity for this source. Methods: XTE J1946+274 was observed by Chandra-ACIS during quiescence in 2013Özbey Arabacı, M. et al.
Advertised on:
102015 -
The radial abundance gradient of chlorine in the Milky WayWe determine the radial abundance gradient of Cl in the Milky Way from H II regions spectra. For the first time, the Cl/H ratios are computed by simply adding ionic abundances and not using an ionization correction factor (ICF). We use a collection of published very deep spectra of Galactic H II regions. We have recalculated the physical conditionsEsteban, C. et al.
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92015 -
s-process enrichment in the planetary nebula NGC 3918. Results from deep echelle spectrophotometryThe chemical content of the planetary nebula NGC 3918 is investigated through deep, high-resolution (R ˜ 40 000) UVES (Ultraviolet-Visual Echelle Spectrograph) at VLT (Very Large Telescope) spectrophotometric data. We identify and measure more than 750 emission lines, making ours one of the deepest spectra ever taken for a planetary nebula. AmongGarcía-Rojas, J. et al.
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92015 -
Ionized gas in the XUV disc of the NGC 1512/1510 systemWe present deep, intermediate-resolution, optical spectroscopy of 136 genuine UV-bright regions located in both the inner and outer regions of NGC 1512. This galaxy is in close interaction with the blue compact dwarf galaxy NGC 1510 and possesses two prominent H I arms where extended ultraviolet complexes are found. Our data were taken using 2dFLópez-Sánchez, Á. R. et al.
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72015 -
Binarity and the Abundance Discrepancy Problem in Planetary NebulaeThe discrepancy between abundances computed using optical recombination lines and collisionally excited lines is a major unresolved problem in nebular astrophysics. Here, we show that the largest abundance discrepancies are reached in planetary nebulae with close binary central stars. We illustrate this using deep spectroscopy of three nebulae withCorradi, R. L. M. et al.
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42015 -
Observing and Reducing IFUs: INTEGRAL and PMAS—Properties of the Ionized Gas in HH 202The reduction of integral field spectroscopy (IFS) data requires several stages and many repetitive operations to convert raw data into, typically, a large number of spectra. Instead there are several semiautomatic data reduction tools and here we present this data reduction process using some of the Image Reduction and Analysis Facility (IRAF)López-Martín, L.
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2014 -
PyNeb: a new tool for analyzing emission lines. I. Code description and validation of resultsAnalysis of emission lines in gaseous nebulae yields direct measures of physical conditions and chemical abundances and is the cornerstone of nebular astrophysics. Although the physical problem is conceptually simple, its practical complexity can be overwhelming since the amount of data to be analyzed steadily increases; furthermore, results dependLuridiana, V. et al.
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12015 -
Physical conditions derived from O II recombination lines in planetary nebulae and their implicationsBased on high quality observations of multiplet V1 of O II and the NLTE atomic computations for O II we study the density and temperature of a sample of PNe. We find that, in general, the densities derived from recombination lines of O II are similar to the densities derived from forbidden lines. This implies that the signature for oxygen richPeimbert, A. et al.
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102014 -
The Cocoon nebula and its ionizing star: do stellar and nebular abundances agree?Context. Main-sequence massive stars embedded in an H ii region should have the same chemical abundances as the surrounding nebular gas+dust. The Cocoon nebula (IC 5146), a close-by Galactic H ii region ionized by a narrow line B0.5 V single star (BD+46 3474), is an ideal target to compare nebular and stellar abundances in detail in the sameGarcía-Rojas, J. et al.
Advertised on:
112014 -
Recent activity of the Be/X-ray binary system SAX J2103.5+4545Aims: We present a multiwavelength study of the Be/X-ray binary system SAX J2103.5+4545 with the goal of better characterizing the transient behaviour of this source. Methods: SAX J2103.5+4545 was observed by Swift/XRT four times in 2007 from April 25 to May 5, and during quiescence in 2012 August 31. In addition, this source has been monitoredCamero, A. et al.
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82014 -
Kinematic study of planetary nebulae in NGC 6822Context. The kinematics of planetary nebulae in external galaxies and in our own is a clue for understanding the behavior of the low- and intermediate-mass stars and their relation with other components of the galaxies. Aims: By measuring precise radial velocities of planetary nebulae (which belong to the intermediate-age population), H ii regionsFlores-Durán, S. N. et al.
Advertised on:
82014 -
Carbon and oxygen abundances from recombination lines in low-metallicity star-forming galaxies. Implications for chemical evolutionWe present deep echelle spectrophotometry of the brightest emission-line knots of the star-forming galaxies He 2-10, Mrk 1271, NGC 3125, NGC 5408, POX 4, SDSS J1253-0312, Tol 1457-262, Tol 1924-416 and the H II region Hubble V in the Local Group dwarf irregular galaxy NGC 6822. The data have been taken with the Very Large Telescope UltravioletMesa-Delgado, A. et al.
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92014 -
The planetary nebula IPHASXJ211420.0+434136 (Ou5): insights into common-envelope dynamical and chemical evolutionWhile analysing the images of the IPHAS (INT/WFC Photometric Hα Survey of the northern Galactic plane) survey, we noticed that the central star of the candidate planetary nebula IPHASXJ211420.0+434136 (also named Ou5) was clearly variable. This is generally considered as an indication of binarity. To confirm it, we performed a photometricCorradi, R. L. M. et al.
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72014 -
The Trace of the CNO Cycle in the Ring Nebula NGC 6888We present new results on the chemical composition of the Galactic ring nebula NGC 6888 surrounding the WN6(h) star WR136. The data are based on deep spectroscopical observations taken with the High Dispersion Spectrograph at the 8.2 m Subaru Telescope. The spectra cover the optical range from 3700 to 7400 Å. The effect of the CNO cycle is wellMesa-Delgado, A. et al.
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42014 -
Deep high spectral resolution spectroscopy and chemical composition of ionized nebulaeHigh spectral resolution spectroscopy has proved to be very useful for the advancement of chemical abundances studies in photoionized nebulae, such as H II regions and planetary nebulae (PNe). Classical analyses make use of the intensity of bright collisionally excited lines (CELs), which have a strong dependence on the electron temperature andGarcía-Rojas, J. et al.
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12014 -
Chemical Evolution and the Galactic Habitable Zone of M31We have computed the Galactic Habitable Zones (GHZs) of the Andromeda galaxy (M31) based on the probability of terrestrial planet formation, which depends on the metallicity (Z) of the interstellar medium, and the number of stars formed per unit surface area. The GHZ was obtained from a chemical evolution model built to reproduce a metallicityMeneses-Goytia, S. et al.
Advertised on:
102013 -
Analysis of chemical abundances in planetary nebulae with [WC] central stars. II. Chemical abundances and the abundance discrepancy factorAims: We present the abundance analysis of 12 planetary nebulae ionized by [WC]-type stars and weak-emission-line stars (wels) obtained from high-resolution spectrophotometric data. Our main aims are to determine the chemical composition of the nebulae and to study the behaviour of the abundance discrepancy problem (ADF) in this type of planetaryGarcía-Rojas, J. et al.
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102013 -
Unveiling shocks in planetary nebulaeThe propagation of a shock wave into a medium is expected to heat the material beyond the shock, producing noticeable effects in intensity line ratios such as [O iii]/Hα. To investigate the occurrence of shocks in planetary nebulae (PNe), we have used all narrow-band [O iii] and Hα images of PNe available in the HST archive to build their [O iii]Guerrero, M. A. et al.
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92013 -
NGC 2579 and the carbon and oxygen abundance gradients beyond the solar circleWe present deep echelle spectrophotometry of the Galactic H II region NGC 2579. The data have been taken with the Very Large Telescope Ultraviolet-Visual Echelle Spectrograph in the 3550-10 400 Å range. This object, which has been largely neglected, shows however a rather high surface brightness, a high ionization degree and is located at aEsteban, C. et al.
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72013 -
Galactic kinematics of Planetary Nebulae with [WC] central starHigh resolution spectra are used to analyze the galactic kinematics and distribution of a sample of planetary nebulae with [WR] and `wel' central star ([WR]PN and WLPN). The circular and peculiar velocities, (V_pec), of the objects were derived. The results are: (a) [WR]PNe are distributed mainly in the galactic disk and they are more concentratedRechy-García, J. S. et al.
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42013
