Population of AGB stars in the outer Galaxy

2018 ◽  
Vol 14 (S343) ◽  
pp. 508-509
Author(s):  
Ryszard Szczerba ◽  
Ilknur Gezer ◽  
Bosco H. K. Yung ◽  
Marta Sewiło
Keyword(s):  
Galactic Plane ◽  
Initial Study ◽  
Asymptotic Giant Branch ◽  
Agb Stars ◽  
Spitzer Space Telescope ◽  
Space Telescope ◽  
Preliminary Results ◽  
Galactic Longitude

AbstractWe present preliminary results of a study aimed at identifying and characterizing the Asymptotic Giant Branch (AGB) stars in the outer Galaxy using the color-color diagram (CCD) that combines the Spitzer Space Telescope and 2MASS photometry: Ks – [8.0] vs. Ks – [24]. Our initial study concentrates on a region in the outer Galactic plane around a galactic longitude l of 105°, where we identified 777 O-rich and 200 C-rich AGB star candidates.

scholarly journals Revealing infrared populations of nearby galaxies using the Spitzer Space Telescope

2009 ◽  
Vol 5 (S262) ◽  
pp. 111-114
Author(s):  
Mikako Matsuura
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Asymptotic Giant Branch ◽  
Evolutionary Stage ◽  
Agb Stars ◽  
Spitzer Space Telescope ◽  
Space Telescope ◽  
Chemical Enrichment ◽  
Nearby Galaxies ◽  
Enrichment Process

AbstractDue to their brightness in infrared, asymptotic giant branch (AGB) stars are in important evolutionary stage to be understood at this wavelength. In particular, in next decades, when the infrared optimised telescopes, such as the JWST and the ELT are in operation, it will be essential to include the AGB phase more precisely into the population synthesis models. However, the AGB phase is still one of the remaining major problems in the stellar evolution. This is because the AGB stellar evolution is strongly affected by the mass-loss process from the stars. It is important to describe mass loss more accurately so as to incorporate it into stellar evolutionary models. Recent observations using the Spitzer Space Telescope (SST) enabled us to make a significant progress in understanding the mass loss from AGB stars. Moreover, the SST large surveys contributed to our understanding of the role of AGB stars in chemical enrichment process in galaxies. Here we present the summary of our recent progress.

scholarly journals A Spitzer Space Telescope survey of extreme asymptotic giant branch stars in M32

2014 ◽  
Vol 446 (2) ◽  
pp. 1584-1596 ◽  
Author(s):  
O. C. Jones ◽  
I. McDonald ◽  
R. M. Rich ◽  
F. Kemper ◽  
M. L. Boyer ◽  
...  
Keyword(s):  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Spitzer Space Telescope ◽  
Space Telescope ◽  
Giant Branch Stars

scholarly journals Planetary nebulae detected in the Spitzer Space Telescope GLIMPSE 3D Legacy Survey

2011 ◽  
Vol 7 (S283) ◽  
pp. 528-529
Author(s):  
Yong Zhang ◽  
Sun Kwok ◽  
Chih-Hao Hsia ◽  
Jun-ichi Nakashima ◽  
Nico Koning
Keyword(s):  
Galactic Plane ◽  
Planetary Nebulae ◽  
Interstellar Extinction ◽  
Optical Observations ◽  
Spitzer Space Telescope ◽  
Good Opportunity ◽  
Mid Infrared ◽  
Space Telescope

AbstractDue to interstellar extinction, optical census of Galactic planetary nebulae (PNs) is highly incomplete, and some compact H ii regions might have been mis-classified as PNs. The problem is particularly severe in the Galactic plane where the extinction in the optical is significant and hampers the detections of PNs. Unlike optical observations, infrared (IR) observations are hardly affected by interstellar extinction, and provide a good opportunity to study highly obscured PNs. In this study, we use the data from the Spitzer Legacy Infrared Mid-Plane Survey Extraordinaire 3D (GLIMPSE 3D) to investigate the mid-infrared (MIR) properties of PNs and PN candidates.

scholarly journals Lithium factories in the Galaxy: novae and AGB stars

2009 ◽  
Vol 5 (S268) ◽  
pp. 395-404 ◽  
Author(s):  
Francesca D'Antona ◽  
Paolo Ventura
Keyword(s):  
Globular Clusters ◽  
Second Generation ◽  
State Of The Art ◽  
The State ◽  
Asymptotic Giant Branch ◽  
Agb Stars ◽  
Preliminary Results ◽  
The Galaxy

AbstractWe review the state of the art in modelling lithium production, through the Cameron–Fowler mechanism, in two stellar sites: during nova explosions and in the envelopes of massive asymptotic giant branch (AGB) stars. We also show preliminary results concerning the computation of lithium yields from super–AGBs, and suggest that super–AGBs of metallicity close to solar may be the most important galactic lithium producers. Finally, we discuss how lithium abundances may help to understand the modalities of formation of the “second generation” stars in globular clusters.

scholarly journals Morphological classification of post-AGB stars

2011 ◽  
Vol 7 (S283) ◽  
pp. 83-86
Author(s):  
Arturo Manchado ◽  
D. Anibal García-Hernández ◽  
Eva Villaver ◽  
Jean Guironnet de Massas
Keyword(s):  
Hubble Space Telescope ◽  
Asymptotic Giant Branch ◽  
Galactic Latitude ◽  
Agb Stars ◽  
Morphological Classification ◽  
Preliminary Results ◽  
Evolutionary Phase ◽  
Complete Study ◽  
Circumstellar Shell ◽  
Pn Stage

AbstractWe present a complete study of the morphology of post-Asymptotic Giant Branch (post-AGB) stars. The post-AGB stage is a very short evolutionary phase between the end of the AGB and the beginning of the Planetary Nebula (PN) stage (between 100 and 10,000 yrs). Post-AGB stars do not show variability and are not hot enough to fully ionize the hydrogen envelope. We have defined the end of the post-AGB phase and the beginning of the PN phase when the star has a temperature of 30000 K. Post-AGB stars have a circumstellar shell that is illuminated by the central stars or partially ionized. However, this circumstellar shell is too small to be resolved by ground-based observations. Thus, we have used the Hubble Space Telescope (HST) database to resolve these shells. 117 post-AGBs were found in this database. Here we present the preliminary results on their morphological classification and the correlation with the galactic latitude. Our preliminary results show that 38% of the sample are stellar-like (S), 31% bipolar (B), 12% multipolar (M) and 19% elliptical (E).

scholarly journals Spitzer Space Telescope spectral observations of AGB stars in the Fornax dwarf spheroidal galaxy

2007 ◽  
Vol 382 (4) ◽  
pp. 1889-1900 ◽  
Author(s):  
M. Matsuura ◽  
A. A. Zijlstra ◽  
J. Bernard-Salas ◽  
J. W. Menzies ◽  
G. C. Sloan ◽  
...  
Keyword(s):  
Agb Stars ◽  
Spitzer Space Telescope ◽  
Space Telescope

scholarly journals Identification of three new protoplanetary nebulae exhibiting the unidentified feature at 21 μm

2011 ◽  
Vol 7 (S283) ◽  
pp. 328-329
Author(s):  
Luciano Cerrigone ◽  
Joseph L. Hora ◽  
Grazia Umana ◽  
Corrado Trigilio ◽  
Alexa Hart ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Spectral Type ◽  
Type A ◽  
Agb Stars ◽  
Spitzer Space Telescope ◽  
Space Telescope ◽  
Protoplanetary Nebulae ◽  
Broad Emission ◽  
Common Nature

AbstractSince its discovery, the feature at 21 μm has been detected in all C-rich proto-PNe of intermediate spectral type (A–G) and – weakly – in a few PNe and AGB stars, but the nature of its carriers remains unknown. In this paper, we show the detection of this feature in the spectra of three new stars obtained with the Spitzer Space Telescope. In the attempt to relate the unidentified feature to other dust features, we retrieved mid-IR spectra of all the 21 μm sources currently known from ISO and Spitzer archives and noticed a correlation between the flux emitted in the 21 μm feature and that emitted at 7 and 11 μm (PAH bands and HAC broad emission). Such a correlation may point to a common nature of the carriers.

Updates on the Ultraviolet Emission from Asymptotic Giant Branch Stars

2018 ◽  
Vol 14 (S343) ◽  
pp. 474-475
Author(s):  
Rodolfo Montez ◽  
Sofia Ramstedt ◽  
Joel H. Kastner ◽  
Wouter Vlemmings
Keyword(s):  
Galaxy Evolution ◽  
Initial Study ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Agb Stars ◽  
Ultraviolet Emission ◽  
Uv Emission ◽  
The Galaxy ◽  
Chromospheric Emission ◽  
Giant Branch Stars

AbstractA comprehensive study of UV emission from asymptotic giant branch (AGB) stars with the Galaxy Evolution Explorer (GALEX) revealed that out of the 316 observed AGB stars, 57% were detected in the near-UV (NUV) bandpass and 12% were detected in the far-UV (FUV) bandpass (Montez et al. 2017). A cross-match between our sample and Gaia DR2 results in parallax estimates for 90% of the sample of AGB stars, compared to only 30% from Hipparcos. This increase allowed us to further probe trends and conclusions of our initial study. Specifically, that the detection of UV emission from AGB stars is subject to proximity and favorable lines of sight in our Galaxy. These improved results support the notion that some of the GALEX-detected UV emission is intrinsic to AGB stars, likely due to a combination of photospheric and chromospheric emission.

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