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Search Results: 1 - 10 of 663177 matches for " R. L. M. Corradi "
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R. L. M. Corradi,A. Mampaso,IPHAS
Revista mexicana de astronomía y astrofísica , 2009,
Abstract: Ongoing and future optical and near-infrared surveys focused on the study of the Galactic plane are brie y presented. Their potential is illustrated by the rst results from IPHAS, the INT Photometric H Survey of the Northern Galactic Plane.
Spectroscopy of planetary nebulae in M33
L. Magrini,M. Perinotto,R. L. M. Corradi,A. Mampaso
Physics , 2003, DOI: 10.1051/0004-6361:20030031
Abstract: Spectroscopic observations of 48 emission-line objects of M33 have been obtained with the multi-object, wide field, fibre spectrograph AF2/WYFFOS at the 4.2m WHT telescope (La Palma, Spain). Line intensities and logarithmic extinction, cbeta, are presented for 42 objects. Their location in the Sabbadin & D'Odorico diagnostic diagram (Halpha/[SII] vs Hlapha/[NII]) suggests that >70% of the candidates are Planetary Nebulae (PNe). Chemical abundances and nebular physical parameters have been derived for the three of the six PNe where the 4363A [OIII] emission line was measurable. These are disc PNe, located within a galactocentric distance of 4.1 kpc, and, to date, they are the farthest PNe with a direct chemical abundance determination. No discrepancy in the Helium, Oxygen and Argon abundances has been found in comparison with corresponding abundances of PNe in our Galaxy. Only a lower limit to the sulphur abundance has been obtained since we could not detect any [SIII] line. N/H appears to be lower than the Galactic value; some possible explanations for this under-abundance are discussed.
New candidate planetary nebulae in M81
L. Magrini,M. Perinotto,R. L. M. Corradi,A. Mampaso
Physics , 2001, DOI: 10.1051/0004-6361:20011301
Abstract: A 34 x 34 arcmin field centred on the spiral galaxy M81 has been searched for emission-line objects using the prime focus wide field camera (WFC) of the 2.54 m Isaac Newton Telescope (La Palma, Spain). A total of 171 candidate planetary nebulae (PNe) are found, 54 of which are in common with the ones detected by Jacoby et al. (1989). The behaviour of PNe excitation as a function of galactocentric distance is examined, and no significant variations are found. The PNe luminosity function is built for the disk and bulge of M81, separately. A distance modulus of 27.92+-0.23 mag is found for disk PNe, in good agreement with previous distance measurements for M81 (Jacoby et al. 1989; Huterer et al. 1995).
L. Sabin,R. L. M. Corradi,A. Mampaso,IPHAS collaboration
Revista mexicana de astronomía y astrofísica , 2011,
Abstract: El censo INT fotométrico en H-alfa (IPHAS) finalizado recientemente, es una nueva herramienta que ayuda en la detección de Nebulosas Planetarias (NPs) al norte del plano Galáctico. De hecho, se ha escaneado ya un área del cielo de 1800 grados cuadrados en donde se han descubierto cientos de nuevas candidatas a NPs localizadas en el plano (que abarca desde el abarrotado y polvoso centro Galáctico hasta el área poco conocida del anticentro). El objetivo de IPHAS es llenar el hueco en la poblacián general de NPs, de aquellas que se localizan en el plano Galáctico, y establecer así un nuevo censo. Presentamos el censo y algunos resultados preliminares sobre las NPs hasta ahora identificadas.
A. Mampaso,R. L. M. Corradi,K. Viironen,L. Sabin
Revista mexicana de astronomía y astrofísica , 2009,
Abstract: The INT photometric H-alpha Survey (IPHAS; http://www.iphas.org) is now near completion. A band of 10 degrees along the Northern Galactic Plane is being imaged in H , r' and i' lters with typically 1 arcsec resolution and a completeness limit better than r'=20 mag. IPHAS is lling in the currently existing gap in the Planetary Nebulae (PNe) population of the Plane: we are on course to tripling the number of PNe known in the northern plane. Many hundreds of candidate PNe, both small diameter (<10 arcsec) and extended, have been identi ed; some are located in areas of particular interest as the Anticenter region. A preliminary analysis of the region from RA=18 to 20h, where the observations are already complete, is presented.
Evidence for binarity in the bipolar planetary nebulae A79, He2-428 and M1-91
M. Rodriguez,R. L. M. Corradi,A. Mampaso
Physics , 2001, DOI: 10.1051/0004-6361:20011123
Abstract: We present low and high resolution long-slit spectra of three bipolar planetary nebulae (PNe) with bright central cores: A79, He2-428 and M1-91. He2-428 and M1-91 have high density (from 10^3.3 to 10^6.5 cm^-3) unresolved nebular cores that indicate that strong mass loss/exchange phenomena are occurring close to their central stars. An F0 star is found at the centre of symmetry of A79; its reddening and distance are consistent with the association of the star with the nebula. The spectrum of the core of He2-428 shows indications of the presence of a hot star with red excess emission, probably arising in a late-type companion. A79 is one of the richest PNe in N and He, the abundances of M1-91 are at the lower end of the range spanned by bipolar PNe, and He2-428 shows very low abundances, similar to those measured for halo PNe. The extended nebulae of A79 and He2-428 have inclined equatorial rings expanding at a velocity of approx. 15 km/s, with kinematical ages 10^4 yr. The association of these aged, extended nebulae with a dense nebular core (He2-428) or a relatively late type star (A79) is interpreted as evidence for the binarity of their nuclei.
Detection of a giant halo around NGC 7027
S. G. Navarro,A. Mampaso,R. L. M. Corradi
Revista mexicana de astronomía y astrofísica , 2002,
Diagnostic diagrams of H II regions in the Local Group
G. Delgado,K. Viironen,A. Mampaso,R. L. M. Corradi
Revista mexicana de astronomía y astrofísica , 2005,
Deep WFC Images of the region around NGC 7027
S. G. Navarro,R. L. M. Corradi,A. Mampaso
Revista mexicana de astronomía y astrofísica , 2003,
Abstract: Presentamos imágenes profundas en los filtros Hα+[NII] y λ5007 de [OIII] de la región circundante a NGC 7027, obtenidas con la cámara de campo amplio (WFC) del telescopio Isaac Newton (INT). En ellas observamos la compleja estructura del medio interestelar en el que se encuentra proyectada esta planetaria e identificamos una estructura esfericamente simétrica rodeándola. Es necesario realizar un análisis cinemática detallado para determinar con exactitud si se trata de material físicamente ligado a la nebulosa planetaria. En ambas imágenes podemos observar los anillos alrededor de NGC 7027, detectados anteriormente por el telescopio espacial Hubble.
V838 Mon and the new class of stars erupting into cool supergiants (SECS)
U. Munari,A. Henden,R. M. L. Corradi,T. Zwitter
Physics , 2002, DOI: 10.1063/1.1518177
Abstract: V838 Mon has undergone one of the most mysterious stellar outbursts on record. The spectrum at maximum closely resembled a cool AGB star, evolving toward cooler temperatures with time, never reaching optically thin conditions or a nebular stage. The latest spectral type recorded is M8-9. The amplitude peaked at DeltaV=9 mag, with the outburst evolution being characterized by a fast rise, three maxima over four months, and a fast decay (possibly driven by dust condensation in the ejecta). BaII, LiI and s-element lines were prominent in the outburst spectra. Strong and wide (500 km/sec) P-Cyg profiles affected low ionization species, while Balmer lines emerged to modest emission only during the central phase of the outburst. A light-echo discovered expanding around the object constrains its distance to 790+/-30 pc, providing M_V=+4.45 in quiescence and M_V=-4.35 at optical maximum (dependent on the still uncertain E(B-V)=0.5 reddening). The visible progenitor resembled a somewhat under-luminous F0 main sequence star, that did not show detectable variability over the last half century. V838 Mon together with M31-RedVar and V4332 Sgr seems to define a new class of astronomical objects: stars that erupt into cool supergiants (SECS). They do not develop optically thin or nebular phases, and deep P-Cyg profiles denounce large mass loss at least in the early outburst phases. Their visible progenitors are located close to the Main Sequence, away from the post-AGB region. After the outburst, the remnants still closely resemble the precursors (same brightness, same spectral type). Many more similar objects could be buried among poorly studied novae that have been classified as Miras on the base of a single spectrum at maximum brightness.
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