scholarly journals Infrared Radiation from Evolved Stars

1990 ◽  
Vol 139 ◽  
pp. 118-120
Author(s):  
William K. Rose
Keyword(s):  
Milky Way ◽  
Background Radiation ◽  
Stellar Winds ◽  
Red Giants ◽  
Total Contribution ◽  
Mid Infrared ◽  
Evolved Stars ◽  
Infrared Measurements ◽  
Infrared Background ◽  
Infrared Continuum

OH/IR stars and carbon stars are examples of evolved stars known to lose mass rapidly. In a recent paper (Rose 1987) we have described calculations of infrared continuum radiation from dust in stellar winds from red giants. We compare calculated radiative models with recent infrared measurements and estimate the total contribution of evolved stars to the mid-infrared background radiation observed from the Milky Way and M31.

scholarly journals 1.16. 4.5 to 11.7 microns spectrophotometric observations of the Galactic bulge by the MIRS/IRTS

1998 ◽  
Vol 184 ◽  
pp. 47-47
Author(s):  
Kin-Wing Chan ◽  
T. L. Roellig ◽  
T. Onaka ◽  
I. Yamamura ◽  
T. Tanabé
Keyword(s):  
Interstellar Medium ◽  
Mass Loss Rate ◽  
Life Time ◽  
High Mass ◽  
Galactic Latitude ◽  
Galactic Bulge ◽  
Stellar Content ◽  
Mid Infrared ◽  
Evolved Stars ◽  
Infrared Background

Using the Mid-Infrared (MIRS) on board the Infrared Telescope in Space (IRTS) we obtained the 4.5 to 11.7 μm spectra of the stellar populations and diffuse interstellar medium in the Galactic bulge (l ≈ 8.7°, b ≈ 2.9, 4.0, 4.7, and 5.7°). Below galactic latitute of 4.0° the mid-infrared background spectra in the bulge are similar to the spectrum of M and K giants. The UIR bands (6.2, 7.7, 8.6, and 11.3 μm) are also detected in these regions and they are likely arising from the diffuse interstellar medium in the bulge. Above galactic latitude of 4.0°, the mid-infrared background spectra are similar to the spectrum of those evolved stars with high mass-loss rate detected by IRAS. One likely interpretation is that this background emission arises predominantly from these stars with very low luminosities that have not been detected by IRAS. The main-sequence life time for such low luminosity evolved stars is at least 10 Gyr, even in the metal poor cases. If these low luminosity evolved stars are metal-rich then the age would be much older. Thus, the existence of a large number (~ 75) of such low luminosity evolved stars in a small region (8′ × 8′) in the bulge would have significant impact on our understanding of the stellar content and the age of the Galactic bulge.

scholarly journals Detection and Photometry of Red Giants in the Magellanic Clouds

1984 ◽  
Vol 108 ◽  
pp. 183-194
Author(s):  
Marc Aaronson
Keyword(s):  
Stellar Population ◽  
Near Infrared ◽  
Formation Rate ◽  
Magellanic Clouds ◽  
Red Giants ◽  
Chemical Enrichment ◽  
Evolved Stars ◽  
Photometric Observations ◽  
Infrared Measurements ◽  
History Of

This review will focus on photometric observations of evolved stars in the Magellanic Clouds. Emphasis is placed on red and near-infrared measurements, as these allow reasonable estimates to be made of bolometric magnitude and temperature for reliable placement in the physical HR diagram. The review is divided into three parts: field stars, cluster stars, and red variables; a summary of the surveys for objects in each of these areas is also given. Particular attention is drawn to the intermediate-age stellar population, as this component appears to be the primary tracer of the star formation rate and chemical enrichment history of the Clouds.

scholarly journals The Nature of the Mid-Infrared Background Radiation in the Galactic Bulge from the Infrared Telescope in Space Observations

1998 ◽  
Vol 505 (1) ◽  
pp. L31-L34 ◽  
Author(s):  
Kin-Wing Chan ◽  
T. L. Roellig ◽  
T. Onaka ◽  
I. Yamamura ◽  
T. Tanabé
Keyword(s):  
Background Radiation ◽  
Galactic Bulge ◽  
Mid Infrared ◽  
Infrared Telescope ◽  
Infrared Background ◽  
Space Observations

scholarly journals A low-cost chopping system and uncooled microbolometer array for ground-based astronomy

2021 ◽  
Author(s):  
M. F. Rashman ◽  
I. A. Steele ◽  
S. D. Bates ◽  
J. H. Knapen
Keyword(s):  
Infrared Imaging ◽  
Low Cost ◽  
Mid Infrared ◽  
Evolved Stars ◽  
Uncooled Microbolometer ◽  
Star Formation In Galaxies ◽  
Infrared Background ◽  
Sensitivity Improvement ◽  
Imaging Instrument ◽  
Infrared Sources

AbstractMid-Infrared imaging is vital for the study of a wide variety of astronomical phenomena, including evolved stars, exoplanets, and dust enshrouded processes such as star formation in galaxies. However, infrared detectors have traditionally been expensive and it is difficult to achieve the sensitivity needed to see beyond the overwhelming mid-infrared background. Here we describe the upgrade and commissioning of a simple prototype, low-cost 10 μ m imaging instrument. The system was built using commercially available components including an uncooled microbolometer focal plane array and chopping system. The system was deployed for a week on the 1.52 m Carlos Sanchez Telescope and used to observe several very bright mid-infrared sources with catalogue fluxes down to $\sim 600$ ∼ 600 Jy. We report a sensitivity improvement of $\sim 4$ ∼ 4 mag over our previous unchopped observations, in line with our earlier predictions.

scholarly journals Introductory Remarks

2001 ◽  
Vol 204 ◽  
pp. 5-15
Author(s):  
P. J. E. Peebles
Keyword(s):  
Star Formation ◽  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Morphological Type ◽  
Star Formation History ◽  
Cosmic Background ◽  
Formation History ◽  
Infrared Background

I review the assumptions and observations that motivate the concept of the extragalactic cosmic background radiation, and the issues of energy accounts and star formation history as a function of galaxy morphological type that figure in the interpretation of the measurements of the extragalactic infrared background.

scholarly journals Measurement and Implications of the Cosmic Microwave Background Spectrum

1996 ◽  
Vol 168 ◽  
pp. 17-29
Author(s):  
John C. Mather
Keyword(s):  
Background Radiation ◽  
Far Infrared ◽  
Big Bang ◽  
Scale Invariant ◽  
Background Spectrum ◽  
Nasa Goddard Space ◽  
Wide Range ◽  
Infrared Background ◽  
Microwave Radiometers ◽  
The Big Bang

The Cosmic Background Explorer (COBE) was developed by NASA Goddard Space Flight Center to measure the diffuse infrared and microwave radiation from the early universe. It also measured emission from nearby sources such as the stars, dust, molecules, atoms, ions, and electrons in the Milky Way, and dust and comets in the Solar System. It was launched 18 November 1989 on a Delta rocket, carrying one microwave instrument and two cryogenically cooled infrared instruments. The Far Infrared Absolute Spectrophotometer (FIRAS) mapped the sky at wavelengths from 0.01 to 1 cm, and compared the CMBR to a precise blackbody. The spectrum of the CMBR differs from a blackbody by less than 0.03%. The Differential Microwave Radiometers (DMR) measured the fluctuations in the CMBR originating in the Big Bang, with a total amplitude of 11 parts per million on a 10° scale. These fluctuations are consistent with scale-invariant primordial fluctuations. The Diffuse Infrared Background Experiment (DIRBE) spanned the wavelength range from 1.2 to 240 μm and mapped the sky at a wide range of solar elongation angles to distinguish foreground sources from a possible extragalactic Cosmic Infrared Background Radiation (CIBR). In this paper we summarize the COBE mission and describe the results from the FIRAS instrument. The results from the DMR and DIRBE were described by Smoot and Hauser at this Symposium.

scholarly journals The relation between AGN hard X-ray emission and mid-infrared continuum from ISO spectra: Scatter and unification aspects

2004 ◽  
Vol 418 (2) ◽  
pp. 465-473 ◽  
Author(s):  
D. Lutz ◽  
R. Maiolino ◽  
H. W. W. Spoon ◽  
A. F. M. Moorwood
Keyword(s):  
Mid Infrared ◽  
X Ray ◽  
Infrared Continuum

scholarly journals Nucleosynthesis of Light-Element Isotopes in Evolved Stars Experiencing Extended Mixing

2009 ◽  
Vol 26 (3) ◽  
pp. 161-167 ◽  
Author(s):  
S. Palmerini ◽  
M. Busso ◽  
E. Maiorca ◽  
R. Guandalini
Keyword(s):  
Mass Transport ◽  
Isotopic Composition ◽  
Light Element ◽  
Asymptotic Giant Branch ◽  
Red Giants ◽  
Agb Stars ◽  
Intermediate Mass ◽  
Evolved Stars ◽  
Magnetic Buoyancy ◽  
Slow Mixing

AbstractWe present computations of nucleosynthesis in red giants and Asymptotic Giant Branch (AGB) stars of Population I experiencing extended mixing. The assumed physical cause for mass transport is the buoyancy of magnetized structures, according to recent suggestions. The peculiar property of such a mechanism is to allow for both fast and slow mixing phenomena, as required for reproducing the spread in Li abundances displayed by red giants and as discussed in an accompanying paper. We explore here the effects of this kind of mass transport on CNO and intermediate-mass nuclei and compare the results with the available evidence from evolved red giants and from the isotopic composition of presolar grains of AGB origin. It is found that a good general accord exists between predictions and measurements; in this framework we also show which type of observational data best constrains the various parameters. We conclude that magnetic buoyancy, allowing for mixing at rather different speeds, can be an interesting scenario to explore for explaining together the abundances of CNO nuclei and of Li.

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