scholarly journals The Galactic H ii Region Luminosity Function at Radio and Infrared Wavelengths

2021 ◽  
Vol 910 (2) ◽  
pp. 159
Author(s):  
J. L. Mascoop ◽  
L. D. Anderson ◽  
Trey. V. Wenger ◽  
Z. Makai ◽  
W. P. Armentrout ◽  
...  
2002 ◽  
Vol 12 ◽  
pp. 146-148
Author(s):  
Ewine F. van Dishoeck ◽  
Floris F.S. van der Tak

AbstractRecent chemical studies of high-mass star-forming regions at submillimeter and infrared wavelengths reveal large variations in the abundances depending on evolutionary state. Such variations can be explained by freezing out of molecules onto grains in the cold collapse phase, followed by evaporation and high-temperature chemical reactions when the young star heats the envelope. Thus, the chemical composition can be a powerful diagnostic tool. A detailed study of a set of infrared-bright massive young stars reveals systematic increases in the gas/solid ratios and abundances of evaporated molecules with temperature. This ‘global heating’ plausibly results from the gradual dispersion of the envelopes. We argue that these objects form the earliest phase of massive star formation, before the ‘hot core’ and ultracompact H II region phase.


2011 ◽  
Vol 735 (2) ◽  
pp. 75 ◽  
Author(s):  
Jong Hwan Lee ◽  
Narae Hwang ◽  
Myung Gyoon Lee

2021 ◽  
Vol 2021 (12) ◽  
pp. 009
Author(s):  
Roy Maartens ◽  
José Fonseca ◽  
Stefano Camera ◽  
Sheean Jolicoeur ◽  
Jan-Albert Viljoen ◽  
...  

Abstract Measurements of galaxy clustering in upcoming surveys such as those planned for the Euclid and Roman satellites, and the SKA Observatory, will be sensitive to distortions from lensing magnification and Doppler effects, beyond the standard redshift-space distortions. The amplitude of these contributions depends sensitively on magnification bias and evolution bias in the galaxy number density. Magnification bias quantifies the change in the observed number of galaxies gained or lost by lensing magnification, while evolution bias quantifies the physical change in the galaxy number density relative to the conserved case. These biases are given by derivatives of the number density, and consequently are very sensitive to the form of the luminosity function. We give a careful derivation of the magnification and evolution biases, clarifying a number of results in the literature. We then examine the biases for a variety of surveys, encompassing galaxy surveys and line intensity mapping at radio and optical/near-infrared wavelengths.


1992 ◽  
Vol 103 ◽  
pp. 815 ◽  
Author(s):  
Richard J. Rand

2006 ◽  
Vol 459 (1) ◽  
pp. L13-L16 ◽  
Author(s):  
T. R. Bradley ◽  
J. H. Knapen ◽  
J. E. Beckman ◽  
S. L. Folkes

1989 ◽  
Vol 101 ◽  
pp. 649 ◽  
Author(s):  
Toby R. Smith ◽  
Robert C., Jr. Kennicutt

1989 ◽  
Vol 337 ◽  
pp. 761 ◽  
Author(s):  
Robert C., Jr. Kennicutt ◽  
B. Kevin Edgar ◽  
Paul W. Hodge

2012 ◽  
Vol 2 (7) ◽  
pp. 15-18
Author(s):  
Mariwan A. Rasheed ◽  
◽  
Mohamad A. Brza

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