Galaxy And Mass Assembly (GAMA): Gas Fuelling of Spiral Galaxies
... density of gas in the disk increases as gas from the IHM continues to be accreted, until it becomes sufficient for the formation of dense, self-gravitating clouds which rapidly collapse to form stars, which then trace the disk as a visible galaxy. The rotationally supported gas in the disk therefore ...
... density of gas in the disk increases as gas from the IHM continues to be accreted, until it becomes sufficient for the formation of dense, self-gravitating clouds which rapidly collapse to form stars, which then trace the disk as a visible galaxy. The rotationally supported gas in the disk therefore ...
The size of AB Doradus A from VLTI/AMBER interferometry⋆
... here. First, using target and calibrators frames, we corrected for the spectral displacement between the photometric spectra of the ATs and the interferometric spectrum; second, we removed the bad pixels and applied the DARK and FLAT corrections; third, we removed the instrumental dispersive effects, ...
... here. First, using target and calibrators frames, we corrected for the spectral displacement between the photometric spectra of the ATs and the interferometric spectrum; second, we removed the bad pixels and applied the DARK and FLAT corrections; third, we removed the instrumental dispersive effects, ...
Circumstellar molecular composition of the oxygen
... 1965 by Neugebauer et al. (1965). It is an extremely red Miratype variable with spectral type ranging from M8.1 to M11.2 and a period around 470 days (Wing & Lockwood 1973). From dust shell motions detected at 11 μm with the ISI interferometer, Hale et al. (1997) deduced a distance of 265 pc. This a ...
... 1965 by Neugebauer et al. (1965). It is an extremely red Miratype variable with spectral type ranging from M8.1 to M11.2 and a period around 470 days (Wing & Lockwood 1973). From dust shell motions detected at 11 μm with the ISI interferometer, Hale et al. (1997) deduced a distance of 265 pc. This a ...
Untitled - NMSU Astronomy
... The speed of light is enormous: 300,000 kilometers per second (km/s) or 186,000 miles per second. Since one year contains 31,536,000 seconds, one ly = 9,460,000,000,000 km! The nearest star, Alpha Centauri, is 4.2 ly away. The Milky Way galaxy is more than 150,000 light years across. The nearest gal ...
... The speed of light is enormous: 300,000 kilometers per second (km/s) or 186,000 miles per second. Since one year contains 31,536,000 seconds, one ly = 9,460,000,000,000 km! The nearest star, Alpha Centauri, is 4.2 ly away. The Milky Way galaxy is more than 150,000 light years across. The nearest gal ...
Water in star-forming regions with Herschel (WISH): II. Evolution of
... Aims. The first systematic survey of spectrally resolved water emission in 29 low-mass (L < 40 L⊙ ) protostellar objects is presented. The sources cover a range of luminosities and evolutionary states. The aim is to characterise the line profiles to distinguish physical components in the beam and ex ...
... Aims. The first systematic survey of spectrally resolved water emission in 29 low-mass (L < 40 L⊙ ) protostellar objects is presented. The sources cover a range of luminosities and evolutionary states. The aim is to characterise the line profiles to distinguish physical components in the beam and ex ...
Prospects for asteroseismic inference on the envelope helium
... Therefore, higher order differences run the risk of there not being enough observable overtones to allow the signature of the second ionization zone of helium to be characterized, and so higher order differences are not suitable for this study. In stars like the Sun the periodicities caused by the s ...
... Therefore, higher order differences run the risk of there not being enough observable overtones to allow the signature of the second ionization zone of helium to be characterized, and so higher order differences are not suitable for this study. In stars like the Sun the periodicities caused by the s ...
Galaxy evolution: A new version of the Besançon Maria A. Czekaj
... decades in Besançon (Robin and Crézé (1986); Robin et al. (2003)). Until now the star production process in that model was based on the drawing from the so called Hess diagrams. Each Galaxy population had one such a diagram, which was calculated once given a particular Initial Mass Function (IMF) ...
... decades in Besançon (Robin and Crézé (1986); Robin et al. (2003)). Until now the star production process in that model was based on the drawing from the so called Hess diagrams. Each Galaxy population had one such a diagram, which was calculated once given a particular Initial Mass Function (IMF) ...
ROSAT Isolated Neutron Stars
... Typical radius ≈ 10 km, masses in the range 0.1 < M/M < 3 (theoretical estimates) Highly relativistic objects M/R ~ 0.15 (M/M)(R/10 km)-1 J/M ~ 0.25 (1 ms/P) (M/M)(R/10 km)2 (the Kerr solution does not describe spacetime outside a rotating star though) ...
... Typical radius ≈ 10 km, masses in the range 0.1 < M/M < 3 (theoretical estimates) Highly relativistic objects M/R ~ 0.15 (M/M)(R/10 km)-1 J/M ~ 0.25 (1 ms/P) (M/M)(R/10 km)2 (the Kerr solution does not describe spacetime outside a rotating star though) ...
The presence of gamma rays in space was known before they were
... Gamma rays were first discovered in 1900 by Villiard, although they become known as gamma rays due to Rutherford. It was not until 1948 when Freeberg and Primakoff theorised that gamma rays are produced in space. The first actual gamma rays detected from space were detected by sensors mounted on a h ...
... Gamma rays were first discovered in 1900 by Villiard, although they become known as gamma rays due to Rutherford. It was not until 1948 when Freeberg and Primakoff theorised that gamma rays are produced in space. The first actual gamma rays detected from space were detected by sensors mounted on a h ...
Protoplanetary Disks and their Evolution
... is rapidly transported through the disk. One possibility for the rapid transport is disk instabilities. Laughlin & Bodenheimer (1994) first suggested that disks would be gravitationally unstable during the early formation stages due to the relatively high mass fraction in the disk versus that accret ...
... is rapidly transported through the disk. One possibility for the rapid transport is disk instabilities. Laughlin & Bodenheimer (1994) first suggested that disks would be gravitationally unstable during the early formation stages due to the relatively high mass fraction in the disk versus that accret ...
Maximizing the ExoEarth Candidate Yield from a Future Direct
... for the desired exposure time. We ignore mission scheduling constraints and realtime costbased decision making that are included in more complex “mission execution simulators” (e.g., Savransky et al. 2010). However, the yield maximization methods described below run rapidly (∼ few seconds on a singl ...
... for the desired exposure time. We ignore mission scheduling constraints and realtime costbased decision making that are included in more complex “mission execution simulators” (e.g., Savransky et al. 2010). However, the yield maximization methods described below run rapidly (∼ few seconds on a singl ...
White dwarf binary
... Low-mass stars with < 2MSun have long lives, never become hot enough to fuse carbon nuclei, and end as carbon white dwarfs Very low-mass stars with < 0.5MSun never become hot enough to fuse helium nuclei, and end as helium white ...
... Low-mass stars with < 2MSun have long lives, never become hot enough to fuse carbon nuclei, and end as carbon white dwarfs Very low-mass stars with < 0.5MSun never become hot enough to fuse helium nuclei, and end as helium white ...
on the evolution of anomalous x-ray pulsars and soft gamma
... their X-ray luminosities, ages, and statistics can be explained with fall back disks with large initial specific angular momentum. The disk evolution models are developed by comparison to self-similar analytical models. The initial disk mass and angular momentum set the viscous timescale. An efficie ...
... their X-ray luminosities, ages, and statistics can be explained with fall back disks with large initial specific angular momentum. The disk evolution models are developed by comparison to self-similar analytical models. The initial disk mass and angular momentum set the viscous timescale. An efficie ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.