Infrared spectra and interstellar reddening of anonymous type II OH/IR stars

1985 ◽  
Vol 290 ◽  
pp. 296 ◽  
Author(s):  
R. D. Gehrz ◽  
J. A. Hackwell ◽  
G. L. Grasdalen ◽  
S. G. Kleinmann ◽  
S. Mason
Keyword(s):  
Infrared Spectra ◽  
Type Ii ◽  
Ir Stars

scholarly journals NEAR-INFRARED SPECTRA AND INTRINSIC LUMINOSITIES OF CANDIDATE TYPE II QUASARS AT 2

2014 ◽  
Vol 788 (1) ◽  
pp. 91 ◽  
Author(s):  
Jenny E. Greene ◽  
Rachael Alexandroff ◽  
Michael A. Strauss ◽  
Nadia L. Zakamska ◽  
Dustin Lang ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Near Infrared ◽  
Type Ii ◽  
Near Infrared Spectra

New OH/IR Stars: Proto-Planetary Nebulae?

1989 ◽  
Vol 131 ◽  
pp. 448-448
Author(s):  
J. Eder ◽  
B. M. Lewis ◽  
Yervant Terzian
Keyword(s):  
Planetary Nebulae ◽  
Point Sources ◽  
Type Ii ◽  
Ir Stars ◽  
First Time ◽  
Right Ascension

The IRAS infrared colors, (60 - 25)μm and (25 - 12)μm, allow efficient identification of Type II OE/IR stars. We present Arecibo1 OH (1612 MHz) observations of 474 IRAS point sources chosen to define the exact regions of the two-color diagram occupied by OH/IR stars. Our observations are complete within the boundary regions of the two-color locus and within the region, 16h right ascension < 22h, 0° < declination < 37°. The sensitivity of the Arecibo telescope allows the identification of many weak sources that would not have been detected by previous surveys and the weak end of the masing phenomenon has been studied for the first time.

scholarly journals Merlin Observations of the OH Maser Emission from IRC+10420

1984 ◽  
Vol 110 ◽  
pp. 321-322
Author(s):  
P. J. Diamond
Keyword(s):  
Angular Size ◽  
Type Ii ◽  
Maser Emission ◽  
Ir Stars ◽  
Maser Sources

MERLIN observations of the 1612 and 1665 Mhz OH masers from the supergiant IRC+10420 reveal several major departures from the usual morphology of OH/IR stars.IRC+10420 is one of the most unusual OH maser sources yet found. It is an F8 supergiant with strong OH maser emission at 1612, 1665 and 1667 Mhz. A north-south optical nebulosity with an angular size of 2 arcsec has been detected (Thompson and Boroson,1977) and its peculiar IR properties are reminiscent of Eta Carina. These characteristics make IRC+10420 unique among Type II OH/IR stars.

scholarly journals The Presence of Water Masers in Color-Selected IRAS Sources

1989 ◽  
Vol 131 ◽  
pp. 450-450
Author(s):  
B. M. Lewis ◽  
D. Engels
Keyword(s):  
Point Source ◽  
Detection Rate ◽  
Type Ii ◽  
Maser Emission ◽  
Companion Star ◽  
Alternative Scenario ◽  
Ir Stars ◽  
Circumstellar Shell ◽  
Water Masers ◽  
Water Maser

Eder, Lewis, and Terzian (1987) examined ∼ 400 sources from the IRAS Point Source Catalogue with colors appropriate to OH/IR stars, for the presence of 1612 MHz emission. We examined a proportion of these objects at Effelsberg for the presence of water-maser emission. In sources with |bII| > 10° which are therefore relatively local, we find a 68% detection rate for water-masers among objects associated with 1612 MHz masers, as opposed to a 17% detection rate among sources with similar colors but without 1612 MHz emission. Those conditions in a circumstellar shell that favor the presence of water-masers also favor the presence of a 1612 MHz maser. These results are consistent with most Type II masers being associated with water-masers. Since Cooke and Elitzur (1985) show that water-masers are collisionally excited, this result excludes stirring of the envelope by a companion star with an associated loss of velocity coherence, as the primary cause for the existence of the color-analogue sources without 1612 MHz masers. We discuss an alternative scenario.

scholarly journals Caracterização da Esmeralda de Pirenópolis (Goiás, Brasil Central) por Espectroscopia no Infravermelho (Ftir)

2000 ◽  
Vol 27 (2) ◽  
pp. 79
Author(s):  
GÊNOVA MARIA PULZ ◽  
ÉLZIO DA SILVA BARBOZA ◽  
TANIA MARIA MARTINI DE BRUM ◽  
ADRIANI FISCHER ◽  
PEDRO LUIZ JUCHEM ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Room Temperature ◽  
Ftir Spectra ◽  
The Other ◽  
Water Molecules ◽  
Type I ◽  
Type Ii ◽  
Central Brazil ◽  
Peak Absorption

The infrared spectra of two natural samples of powdered emerald from Pirenópolis (Goiás State, Central Brazil) were measured at room temperature (~ 20ºC). Water molecules occur in two different configurations. Three absorption peaks (3656, 3592 and 1624 cm-1) record the vibrations of the type-II H2O. The peak absorption at 3691 cm-1 is assigned to type- I H2O vibrations. In addition, CO2 (2358 cm-1) and CH4 (2927-2925 cm-1) molecules were also detected in the FTIR spectra. These data can be applied to distinguish the Pirenópolis gem from the other Brazilian emeralds as well as its synthetic equivalents.

Type II Solar Radio Bursts over Solar Cycle 21

1994 ◽  
Vol 144 ◽  
pp. 283-284
Author(s):  
G. Maris ◽  
E. Tifrea
Keyword(s):  
Solar Radio ◽  
Interplanetary Space ◽  
Impulsive Phase ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Strong Energy ◽  
Mass Ejection ◽  
Geophysical Effect ◽  
Radio Event

The type II solar radio bursts produced by a shock wave passing through the solar corona are one of the most frequently studied solar activity phenomena. The scientific interest in this type of phenomenon is due to the fact that the presence of this radio event in a solar flare is an almost certain indicator of a future geophysical effect. The origin of the shock waves which produce these bursts is not at all simple; besides the shocks which are generated as a result of a strong energy release during the impulsive phase of a flare, there are also the shocks generated by a coronal mass ejection or the shocks which appear in the interplanetary space due to the supplementary acceleration of the solar particles.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Ultrastructure of pulmonary microvasculature in acute endotoxemia

1978 ◽  
Vol 36 (2) ◽  
pp. 470-471
Author(s):  
R. G. Gerrity ◽  
M. Richardson
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Alveolar Epithelium ◽  
Endothelial Damage ◽  
Capillary Endothelium ◽  
Type Ii Cells ◽  
Type Ii ◽  
Interstitial Edema ◽  
Pulmonary Capillaries ◽  
Lung Ultrastructure ◽  
Fibrin Thrombi

Dogs were injected intravenously with E_. coli endotoxin (2 mg/kg), and lung samples were taken at 15 min., 1 hr. and 24 hrs. At 15 min., occlusion of pulmonary capillaries by degranulating platelets and polymorphonuclear leukocytes (PML) was evident (Fig. 1). Capillary endothelium was intact but endothelial damage in small arteries and arterioles, accompanied by intraalveolar hemorrhage, was frequent (Fig. 2). Sloughing of the surfactant layer from alveolar epithelium was evident (Fig. 1). At 1 hr., platelet-PML plugs were no longer seen in capillaries, the endothelium of which was often vacuolated (Fig. 3). Interstitial edema and destruction of alveolar epithelium were seen, and type II cells had discharged their granules into the alveoli (Fig. 4). At 24 hr. phagocytic PML's were frequent in peripheral alveoli, while centrally, alveoli and vessels were packed with fibrin thrombi and PML's (Fig. 5). In similar dogs rendered thrombocytopenic with anti-platelet serum, lung ultrastructure was similar to that of controls, although PML's were more frequently seen in capillaries in the former (Fig. 6).

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