The excitation of the infrared emission from visual reflection nebulae

2008 ◽  
pp. 134-139
Author(s):  
K. Sellgren ◽  
M. W. Castelaz ◽  
M. W. Werner ◽  
L. Luan
Keyword(s):  
Infrared Emission ◽  
Reflection Nebulae

Two New T Tauri stars and a Candidate FU Orionis Star associated with Bok Globules

1997 ◽  
Vol 163 ◽  
pp. 839-839
Author(s):  
J. L. Yun ◽  
M. Moreira
Keyword(s):  
Infrared Emission ◽  
T Tauri Stars ◽  
Emission Lines ◽  
Young Stellar Objects ◽  
Spectral Energy ◽  
Energy Distributions ◽  
Stellar Objects ◽  
T Tauri ◽  
Bok Globules ◽  
Reflection Nebulae

AbstractWe present photometric and spectroscopic evidence of two new T Tauri stars formed in the conditions of isolated small Bok globules. The spectral energy distributions of these objects display excess infrared emission, they are associated with optical reflection nebulae, and their optical spectra reveal Balmer emission lines and the Li I λ6707 Å absorption line. Additionnally, we report the discovery of what is likely to be a new FU Orionis star seen towards Bok globule CB34. The star is about 4 magnitudes brighter than it appears on the Palomar plates and is associated with the aggregate of young stellar objects forming in Bok globule CB34.

Infrared Emission from Reflection Nebulae

1989 ◽  
Vol 135 ◽  
pp. 103-108
Author(s):  
K. Sellgren
Keyword(s):  
Interstellar Dust ◽  
Infrared Emission ◽  
Continuum Emission ◽  
Large Molecules ◽  
Fundamental Component ◽  
Small Grains ◽  
Reflection Nebulae

Observations of 1–25 μm. continuum emission and the interstellar infrared emission features in reflection nebulae are reviewed. These observations place important constraints on models of very small grains or large molecules such as PAHs, which these models must address in order to understand this fundamental component of interstellar dust.

scholarly journals Extended near-infrared emission from visual reflection nebulae

1983 ◽  
Vol 271 ◽  
pp. L13 ◽  
Author(s):  
K. Sellgren ◽  
M. W. Werner ◽  
H. L. Dinerstein
Keyword(s):  
Near Infrared ◽  
Infrared Emission ◽  
Near Infrared Emission ◽  
Reflection Nebulae

scholarly journals A Survey of Near-Infrared Emission in Visual Reflection Nebulae

1996 ◽  
Vol 102 ◽  
pp. 369 ◽  
Author(s):  
K. Sellgren ◽  
M. W. Werner ◽  
L. J. Allamandola
Keyword(s):  
Near Infrared ◽  
Infrared Emission ◽  
Near Infrared Emission ◽  
Reflection Nebulae

Detection and Characterization of earth-like Planets

1997 ◽  
Vol 161 ◽  
pp. 299-311 ◽  
Author(s):  
Jean Marie Mariotti ◽  
Alain Léger ◽  
Bertrand Mennesson ◽  
Marc Ollivier
Keyword(s):  
Direct Detection ◽  
Contrast Ratio ◽  
Angular Size ◽  
Physical Nature ◽  
Major Axis ◽  
Infrared Emission ◽  
Space Technology ◽  
Semi Major Axis ◽  
Earth Like Planets ◽  
Visible Wavelengths

AbstractIndirect methods of detection of exo-planets (by radial velocity, astrometry, occultations,...) have revealed recently the first cases of exo-planets, and will in the near future expand our knowledge of these systems. They will provide statistical informations on the dynamical parameters: semi-major axis, eccentricities, inclinations,... But the physical nature of these planets will remain mostly unknown. Only for the larger ones (exo-Jupiters), an estimate of the mass will be accessible. To characterize in more details Earth-like exo-planets, direct detection (i.e., direct observation of photons from the planet) is required. This is a much more challenging observational program. The exo-planets are extremely faint with respect to their star: the contrast ratio is about 10−10at visible wavelengths. Also the angular size of the apparent orbit is small, typically 0.1 second of arc. While the first point calls for observations in the infrared (where the contrast goes up to 10−7) and with a coronograph, the latter implies using an interferometer. Several space projects combining these techniques have been recently proposed. They aim at surveying a few hundreds of nearby single solar-like stars in search for Earth-like planets, and at performing a low resolution spectroscopic analysis of their infrared emission in order to reveal the presence in the atmosphere of the planet of CO H2O and O3. The latter is a good tracer of the presence of oxygen which could be, like on our Earth, released by biological activity. Although extremely ambitious, these projects could be realized using space technology either already available or in development for others missions. They could be built and launched during the first decades on the next century.

Infrared Emission Spectroscopy as a Reliability Tool

1999 ◽  
Author(s):  
Q. Kim ◽  
S. Kayali
Keyword(s):  
Spatial Resolution ◽  
Emission Spectroscopy ◽  
Hot Spot ◽  
Cost Effective ◽  
Infrared Emission ◽  
Test System ◽  
Operating Conditions ◽  
Yield Enhancement ◽  
Infrared Emission Spectroscopy ◽  
Channel Temperature

Abstract In this paper, we report on a non-destructive technique, based on IR emission spectroscopy, for measuring the temperature of a hot spot in the gate channel of a GaAs metal/semiconductor field effect transistor (MESFET). A submicron-size He-Ne laser provides the local excitation of the gate channel and the emitted photons are collected by a spectrophotometer. Given the state of our experimental test system, we estimate a spectral resolution of approximately 0.1 Angstroms and a spatial resolution of approximately 0.9 μm, which is up to 100 times finer spatial resolution than can be obtained using the best available passive IR systems. The temperature resolution (<0.02 K/μm in our case) is dependent upon the spectrometer used and can be further improved. This novel technique can be used to estimate device lifetimes for critical applications and measure the channel temperature of devices under actual operating conditions. Another potential use is cost-effective prescreening for determining the 'hot spot' channel temperature of devices under normal operating conditions, which can further improve device design, yield enhancement, and reliable operation. Results are shown for both a powered and unpowered MESFET, demonstrating the strength of our infrared emission spectroscopy technique as a reliability tool.

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