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Author Sargent, B.A.; Srinivasan, S.; Speck, A.; Volk, K.; Kemper, C.; Reach, W.T.; Lagadec, E.; Bernard, J.-P.; McDonald, I.; Meixner, M.
Title Spitzer-IRS Spectroscopic Studies of Oxygen-Rich Asymptotic Giant Branch Star and Red Supergiant Star Dust Properties Type Conference Article
Year 2015 Publication Abbreviated Journal
Volume Issue Pages 216.03-216.03
Keywords
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title American Astronomical Society Meeting Abstracts
Series Volume 225 Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes proceedings Approved no
Call Number ASIAA @ ciska @ Serial 41812
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Author Sloan, G.C.; Groenewegen, M.; Srinivasan, S.; Lagadec, E.; Kraemer, K.E.; McDonald, I.; Boyer, M.L.; Zijlstra, A.; Kemper, C.
Title Dust and metallicity in carbon stars Type Conference Article
Year 2015 Publication Abbreviated Journal
Volume Issue Pages 216.04-216.04
Keywords
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title American Astronomical Society Meeting Abstracts
Series Volume 225 Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes proceedings Approved no
Call Number ASIAA @ ciska @ Serial 41813
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Author Naslim, N.; Kemper, F.; Madden, S.C.; Hony, S.; Chu, Y.-H.; Galliano, F.; Bot, C.; Yang, Y.; Seok, J.; Oliveira, J.M.; van Loon, J.T.; Meixner, M.; Li, A.; Hughes, A.; Gordon, K.D.; Otsuka, M.; Hirashita, H.; Morata, O.; Lebouteiller, V.; Indebetouw, R.; Srinivasan, S.; Bernard, J.-P.; Reach, W.T.
Title Molecular hydrogen emission in the interstellar medium of the Large Magellanic Cloud Type Journal Article
Year 2015 Publication Mon.~Not.~R.~Astron.~Soc. Abbreviated Journal
Volume 446 Issue 3 Pages 2490-2504
Keywords ISM: molecules; photodissociation region (PDR); galaxies: ISM; Magellanic Cloud; infrared: ISM
Abstract We present the detection and analysis of molecular hydrogen emission towards ten interstellar regions in the Large Magellanic Cloud. We examined low-resolution infrared spectral maps of 12 regions obtained with the Spitzer infrared spectrograph (IRS). The pure rotational 0-0 transitions of H2 at 28.2 and 17.1 μm are detected in the IRS spectra for 10 regions. The higher level transitions are mostly upper limit measurements except for three regions, where a 3σ detection threshold is achieved for lines at 12.2 and 8.6 μm. The excitation diagrams of the detected H2 transitions are used to determine the warm H2 gas column density and temperature. The single-temperature fits through the lower transition lines give temperatures in the range 86-137 K. The bulk of the excited H2 gas is found at these temperatures and contributes ˜5-17 per cent to the total gas mass. We find a tight correlation of the H2 surface brightness with polycyclic aromatic hydrocarbon and total infrared emission, which is a clear indication of photoelectric heating in photodissociation regions. We find the excitation of H2 by this process is equally efficient in both atomic- and molecular-dominated regions. We also present the correlation of the warm H2 physical conditions with dust properties. The warm H2 mass fraction and excitation temperature show positive correlations with the average starlight intensity, again supporting H2 excitation in photodissociation regions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes refereed; Owner: ciska; Added to JabRef: 2015.04.15 Approved no
Call Number ASIAA @ ciska @ Serial 41815
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Author Ruffle, P.M.E.; Kemper, F.; Jones, O.C.; Sloan, G.C.; Kraemer, K.E.; Woods, P.M.; Boyer, M.L.; Srinivasan, S.; Antoniou, V.; Lagadec, E.; Matsuura, M.; McDonald, I.; Oliveira, J.M.; Sargent, B.A.; Sewiło, M.; Szczerba, R.; van Loon, J.T.; Volk, K.; Zijlstra, A.A.
Title Spitzer infrared Spectrograph point source classification in the Small Magellanic Cloud Type Journal Article
Year 2015 Publication Mon.~Not.~R.~Astron.~Soc. Abbreviated Journal
Volume Issue Pages
Keywords my_papers
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes submitted; Owner: ciska; Added to JabRef: 2015.03.04 Approved no
Call Number ASIAA @ ciska @ Serial 41816
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Author Zhao-Geisler, R.; Köhler, R.; Kemper, F.; Kerschbaum, F.; Mayer, A.; Quirrenbach, A.; Lopez, B.
Title Spectro-imaging of the asymmetric inner molecular and dust shell region of the Mira variable W Hya with MIDI/VLTI Type Journal Article
Year 2015 Publication Pub.~Astron.~Soc.~Pacific Abbreviated Journal
Volume Issue Pages
Keywords my_papers
Abstract We have observed W Hya, one of the closest and best studied oxygen-rich evolved star, in the dust
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes submitted; Owner: ciska; Added to JabRef: 2015.04.15 Approved no
Call Number ASIAA @ ciska @ Serial 41817
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Author Jones, O.C.; McDonald, I.; Rich, R.M.; Kemper, F.; Boyer, M.L.; Zijlstra, A.A.; Bendo, G.J.
Title A Spitzer Space Telescope survey of extreme asymptotic giant branch stars in M32 Type Journal Article
Year 2015 Publication Mon.~Not.~R.~Astron.~Soc. Abbreviated Journal
Volume 446 Issue 2 Pages 1584-1596
Keywords stars: AGB and post-AGB; stars: late-type; stars: mass-loss; galaxies: individual: M32; galaxies: stellar content; infrared: stars
Abstract We investigate the population of cool, evolved stars in the Local Group dwarf elliptical galaxy M32, using Infrared Array Camera observations from the Spitzer Space Telescope. We construct deep mid-infrared colour-magnitude diagrams for the resolved stellar populations within 3.5 arcmin of M32's centre, and identify those stars that exhibit infrared excess. Our data are dominated by a population of luminous, dust-producing stars on the asymptotic giant branch (AGB) and extend to approximately 3 mag below the AGB tip. We detect for the first time a sizeable population of `extreme' AGB stars, highly enshrouded by circumstellar dust and likely completely obscured at optical wavelengths. The total dust-injection rate from the extreme AGB candidates is measured to be 7.5 × 10-7 M⊙ yr-1, corresponding to a gas mass-loss rate of 1.5 × 10-4 M⊙ yr-1. These extreme stars may be indicative of an extended star formation epoch between 0.2 and 5 Gyr ago.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes refereed; Owner: ciska; Added to JabRef: 2015.04.15 Approved no
Call Number ASIAA @ ciska @ Serial 41992
Permanent link to this record
 

 
Author Naslim, N.; Kemper, F.; Madden, S.C.; Hony, S.; Chu, Y.-H.; Galliano, F.; Bot, C.; Yang, Y.; Seok, J.; Oliveira, J.M.; van Loon, J.T.; Meixner, M.; Li, A.; Hughes, A.; Gordon, K.D.; Otsuka, M.; Hirashita, H.; Morata, O.; Lebouteiller, V.; Indebetouw, R.; Srinivasan, S.; Bernard, J.-P.; Reach, W.T.
Title Molecular hydrogen emission in the interstellar medium of the Large Magellanic Cloud Type Journal Article
Year 2015 Publication Mon.~Not.~R.~Astron.~Soc. Abbreviated Journal
Volume 446 Issue 3 Pages 2490-2504
Keywords ISM: molecules; photodissociation region (PDR); galaxies: ISM; Magellanic Cloud; infrared: ISM
Abstract We present the detection and analysis of molecular hydrogen emission towards ten interstellar regions in the Large Magellanic Cloud. We examined low-resolution infrared spectral maps of 12 regions obtained with the Spitzer infrared spectrograph (IRS). The pure rotational 0-0 transitions of H2 at 28.2 and 17.1 μm are detected in the IRS spectra for 10 regions. The higher level transitions are mostly upper limit measurements except for three regions, where a 3σ detection threshold is achieved for lines at 12.2 and 8.6 μm. The excitation diagrams of the detected H2 transitions are used to determine the warm H2 gas column density and temperature. The single-temperature fits through the lower transition lines give temperatures in the range 86-137 K. The bulk of the excited H2 gas is found at these temperatures and contributes ˜5-17 per cent to the total gas mass. We find a tight correlation of the H2 surface brightness with polycyclic aromatic hydrocarbon and total infrared emission, which is a clear indication of photoelectric heating in photodissociation regions. We find the excitation of H2 by this process is equally efficient in both atomic- and molecular-dominated regions. We also present the correlation of the warm H2 physical conditions with dust properties. The warm H2 mass fraction and excitation temperature show positive correlations with the average starlight intensity, again supporting H2 excitation in photodissociation regions.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes refereed; Owner: ciska; Added to JabRef: 2015.04.15 Approved no
Call Number ASIAA @ ciska @ Serial 42038
Permanent link to this record
 

 
Author Ruffle, P.M.E.; Kemper, F.; Jones, O.C.; Sloan, G.C.; Kraemer, K.E.; Woods, P.M.; Boyer, M.L.; Srinivasan, S.; Antoniou, V.; Lagadec, E.; Matsuura, M.; McDonald, I.; Oliveira, J.M.; Sargent, B.A.; Sewiło, M.; Szczerba, R.; van Loon, J.T.; Volk, K.; Zijlstra, A.A.
Title Spitzer infrared Spectrograph point source classification in the Small Magellanic Cloud Type Journal Article
Year 2015 Publication Mon.~Not.~R.~Astron.~Soc. Abbreviated Journal
Volume Issue Pages
Keywords my_papers
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes submitted; Owner: ciska; Added to JabRef: 2015.03.04 Approved no
Call Number ASIAA @ ciska @ Serial 42053
Permanent link to this record
 

 
Author Sargent, B.A.; Srinivasan, S.; Speck, A.; Volk, K.; Kemper, C.; Reach, W.T.; Lagadec, E.; Bernard, J.-P.; McDonald, I.; Meixner, M.
Title Spitzer-IRS Spectroscopic Studies of Oxygen-Rich Asymptotic Giant Branch Star and Red Supergiant Star Dust Properties Type Conference Article
Year 2015 Publication Abbreviated Journal
Volume Issue Pages 216.03-216.03
Keywords
Abstract We analyze the dust emission features seen in Spitzer Space Telescope Infrared Spectrograph (IRS) spectra of Oxygen-rich (O-rich) asymptotic giant branch (AGB) and red supergiant (RSG) stars. The spectra come from the Spitzer Legacy program SAGE-Spectroscopy (PI: F. Kemper) and other archival Spitzer-IRS programs. The broad 10 and 20 micron emission features attributed to amorphous dust of silicate composition seen in the spectra show evidence for systematic differences in the centroid of both emission features between O-rich AGB and RSG populations. Radiative transfer modeling using the GRAMS grid of models of AGB and RSG stars suggests that the centroid differences are due to differences in dust properties. We present an update of our investigation of differences in dust composition, size, shape, etc that might be responsible for these spectral differences. We explore how these differences may arise from the different circumstellar environments around RSG and O-rich AGB stars. BAS acknowledges funding from NASA ADAP grant NNX13AD54G.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title American Astronomical Society Meeting Abstracts
Series Volume 225 Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes proceedings; Owner: ciska; Added to JabRef: 2015.04.16 Approved no
Call Number ASIAA @ ciska @ Serial 42059
Permanent link to this record
 

 
Author Sloan, G.C.; Groenewegen, M.; Srinivasan, S.; Lagadec, E.; Kraemer, K.E.; McDonald, I.; Boyer, M.L.; Zijlstra, A.; Kemper, C.
Title Dust and metallicity in carbon stars Type Conference Article
Year 2015 Publication Abbreviated Journal
Volume Issue Pages 216.04-216.04
Keywords
Abstract The Infrared Spectrograph on the Spitzer Space Telescope observed over 200 carbon stars in nearby metal-poor dwarf galaxies. These spectra probe how the quantity and composition of dust produced by carbon stars depend on initial metallicity, initial mass, and pulsational properties. For stars to produce significant quantities of dust, they must be pulsating in the fundamental mode with strong amplitudes. The spectra confirm that carbon stars with longer pulsation periods produce more dust and that the amount of dust shows no strong dependence on metallicity. This sample includes more carbon stars with low mass and reveals that for a given pulsation period, higher-mass stars produce less dust. Evidence is building for the layering of dust grains, with SiC cores in grains produced by metal-rich carbon stars, and mantles of MgS around grains in all embedded stars.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title American Astronomical Society Meeting Abstracts
Series Volume 225 Series Issue Edition
ISSN (up) ISBN Medium
Area Expedition Conference
Notes proceedings; Owner: ciska; Added to JabRef: 2015.04.16 Approved no
Call Number ASIAA @ ciska @ Serial 42063
Permanent link to this record