The phenomena of astrophysical masers are not new by any means
... power density. This is emitted uniformly in all directions and though not nearly as powerful as the amplified photon flux of frequency v, it requires a filter to remove it from the amplified signal. Astrophysical masers also resemble random lasers in that, unlike conventional masers and lasers, the ...
... power density. This is emitted uniformly in all directions and though not nearly as powerful as the amplified photon flux of frequency v, it requires a filter to remove it from the amplified signal. Astrophysical masers also resemble random lasers in that, unlike conventional masers and lasers, the ...
aaswinter06
... • The detailed light curve is unlike that of a supernova, nova, or any other type of variable star (1,2,3). During the outburst, V838 Mon was found to have a maximum effective temperature of an A – F star at the optical maximum in February 2002. The effective temperature then cooled to a very low ~8 ...
... • The detailed light curve is unlike that of a supernova, nova, or any other type of variable star (1,2,3). During the outburst, V838 Mon was found to have a maximum effective temperature of an A – F star at the optical maximum in February 2002. The effective temperature then cooled to a very low ~8 ...
aaswinter07ppt
... background of this poster and the color picture below) ACS showing what is interpreted as a “light echo” from the eruption (1). A summary of the of the major results of observations since the eruption are: • The detailed light curve is unlike that of a supernova, nova, or any other type of variable ...
... background of this poster and the color picture below) ACS showing what is interpreted as a “light echo” from the eruption (1). A summary of the of the major results of observations since the eruption are: • The detailed light curve is unlike that of a supernova, nova, or any other type of variable ...
Spectral Line VLBI - Australia Telescope National Facility
... Properties of a Maser • The maser components are extremely small (mas) and narrow (fractions of a km/s) Measure position and velocity of components with great accuracy ...
... Properties of a Maser • The maser components are extremely small (mas) and narrow (fractions of a km/s) Measure position and velocity of components with great accuracy ...
Molecular Line Emission in Star
... Velocities are usually calculated respect to the Local Standard of Rest (LSR), an ideal point in rotation around the Galactic centre as far as the Sun. The relationship between velocity and frequency is: ...
... Velocities are usually calculated respect to the Local Standard of Rest (LSR), an ideal point in rotation around the Galactic centre as far as the Sun. The relationship between velocity and frequency is: ...
Presentazione di PowerPoint
... • H2 NIR emission jet. Hunter et al. (1999): • OVRO SiO jet and HCO+ outflow; • OVRO 88 GHz source (coincident with the 8.4 GHz source) The radio flux and the bolometric luminosity of the source both indicate the presence of a massive object (M 10 M). Zhang et al. (2002): VLA NH3 compact structur ...
... • H2 NIR emission jet. Hunter et al. (1999): • OVRO SiO jet and HCO+ outflow; • OVRO 88 GHz source (coincident with the 8.4 GHz source) The radio flux and the bolometric luminosity of the source both indicate the presence of a massive object (M 10 M). Zhang et al. (2002): VLA NH3 compact structur ...
High-mass star-forming cloud G0.38+0.04 in the Galactic center dust
... Sgr B2 (M) are also the only H2 CO maser sources with corresponding SiO maser detections and vice versa, though the sample of regions explored in both tracers is small. This high detection rate of masers in star-forming regions within the CMZ, despite limited statistical information, suggests that H ...
... Sgr B2 (M) are also the only H2 CO maser sources with corresponding SiO maser detections and vice versa, though the sample of regions explored in both tracers is small. This high detection rate of masers in star-forming regions within the CMZ, despite limited statistical information, suggests that H ...
6.7 GHz Methanol Masers and the GBT
... • The methodology is to combine the initial mass function with the star formation law in the Galaxy (as a function of position) to create a distribution of massive stars as a function of galactic longitude. • Then, assuming that every massive star excites a methanol maser during its birth, one can d ...
... • The methodology is to combine the initial mass function with the star formation law in the Galaxy (as a function of position) to create a distribution of massive stars as a function of galactic longitude. • Then, assuming that every massive star excites a methanol maser during its birth, one can d ...
Nature template - PC Word 97
... full polarization monitoring of SiO masers, sampling at least once per hour, with high spatial resolution. This will ultimately allow us to distinguish between the proposed scenarios and to investigate the fate of inner planetary systems around solar-type stars entering their AGB phase. All our know ...
... full polarization monitoring of SiO masers, sampling at least once per hour, with high spatial resolution. This will ultimately allow us to distinguish between the proposed scenarios and to investigate the fate of inner planetary systems around solar-type stars entering their AGB phase. All our know ...
What is a T Tauri star?
... • Near-IR: hot inner disk: dust and gas • mid-IR -> sub-mm: dusty disk emission • Solar + accretional energy ...
... • Near-IR: hot inner disk: dust and gas • mid-IR -> sub-mm: dusty disk emission • Solar + accretional energy ...
Collaborations with East Asian VLBI stations
... • Pitch angle of Perseus arm 16 +/- 3 deg four arm spiral ? ...
... • Pitch angle of Perseus arm 16 +/- 3 deg four arm spiral ? ...
Galactic Parameters from Masers with Trigonometric Parallaxes
... Positions for one 12 GHz maser spot in W3OH relative to 3 background sources (offset from each other for clarity). The data show the sinusoidal parallax signature superposed on the proper motions. ...
... Positions for one 12 GHz maser spot in W3OH relative to 3 background sources (offset from each other for clarity). The data show the sinusoidal parallax signature superposed on the proper motions. ...
Joining the Party - Lincoln-Sudbury Regional High School
... collapse of a cool molecular cloud. In the final stages of this collapse, the cloud’s core becomes sufficiently hot and the gas is under enough pressure for fusion reactions to begin: this is a young stellar object (YSO), a baby star. Obviously, astronomers are very interested in the stages of the c ...
... collapse of a cool molecular cloud. In the final stages of this collapse, the cloud’s core becomes sufficiently hot and the gas is under enough pressure for fusion reactions to begin: this is a young stellar object (YSO), a baby star. Obviously, astronomers are very interested in the stages of the c ...
Stages of star formation (the classical view)
... A rough analysis of the transfer equation shows that intensity is amplified exponentially. The brightness temperature of a maser transition can be extremely high. For example, for Tex= -20 K, |τ0| = 20, we have T0 = 1010 K. Maser radiations is produced in very compact regions (maser spots), and the ...
... A rough analysis of the transfer equation shows that intensity is amplified exponentially. The brightness temperature of a maser transition can be extremely high. For example, for Tex= -20 K, |τ0| = 20, we have T0 = 1010 K. Maser radiations is produced in very compact regions (maser spots), and the ...
AstronomicalSpectroscopy
... Atomic emissions beyond the visible spectrum • Note that the emission extends over a range of frequencies. • The term often refers to the visible light emission spectrum, although it extends to the whole electromagnetic spectrum, from the low energy radio waves up to high energy gamma rays. ...
... Atomic emissions beyond the visible spectrum • Note that the emission extends over a range of frequencies. • The term often refers to the visible light emission spectrum, although it extends to the whole electromagnetic spectrum, from the low energy radio waves up to high energy gamma rays. ...
Main Requirements of the Laser • Optical Resonator Cavity • Laser
... Axial modes within Transition Gaussian • Each axial mode is Gaussian shape narrower than transition peak • eg for L=1 m Argon laser at 514 nm c 3.00 x10 8 c 3.00 x10 8 ∆ν = ...
... Axial modes within Transition Gaussian • Each axial mode is Gaussian shape narrower than transition peak • eg for L=1 m Argon laser at 514 nm c 3.00 x10 8 c 3.00 x10 8 ∆ν = ...
Quantum effects in astrophysics
... the spectrum, this corresponds to a line shift on the order of 1.5 angstroms. This shift could be easily detected, yet, for many years, no deuterium was ever detected in any astronomical object. In contrast, the terrestrial abundance of deuterium is readily measured and is roughly 2x10-4 by fraction ...
... the spectrum, this corresponds to a line shift on the order of 1.5 angstroms. This shift could be easily detected, yet, for many years, no deuterium was ever detected in any astronomical object. In contrast, the terrestrial abundance of deuterium is readily measured and is roughly 2x10-4 by fraction ...
Radio observations of the planetary nebula around the OH/IR Star
... the sky. An old UKST Hα plate which includes the PN region exists in the archive. This exposure (HA2307) was taken in 1976 for John Meaburn on fast but coarse-grained O-9804 emulsion with a mo- ...
... the sky. An old UKST Hα plate which includes the PN region exists in the archive. This exposure (HA2307) was taken in 1976 for John Meaburn on fast but coarse-grained O-9804 emulsion with a mo- ...
Molecular Outflows Driven by Young Brown Dwarfs And VLMs. New
... Tau 6 and FU Tau A with high angular resolution observations with the Plateau de Bure Interferometer (PdBI). These sources were chosen because their associated CO emission showed clear evidence of an outflow and / or their spectral energy distributions (SEDs) showed strong evidence of a massive accr ...
... Tau 6 and FU Tau A with high angular resolution observations with the Plateau de Bure Interferometer (PdBI). These sources were chosen because their associated CO emission showed clear evidence of an outflow and / or their spectral energy distributions (SEDs) showed strong evidence of a massive accr ...
Interstellar Medium and Star Formation
... Extinction was known since 1847 (though not taken seriously in Galaxy models) Reddening discovered by Trumpler (1930) Wavelength dependence established obscuration as due to small particles Reddening proportional to NH ...
... Extinction was known since 1847 (though not taken seriously in Galaxy models) Reddening discovered by Trumpler (1930) Wavelength dependence established obscuration as due to small particles Reddening proportional to NH ...
Problem Set 2
... that the disk’s total luminosity is LD = 2πh2R I(R = 0). For the Milky Way, LD ≈ 1.5 × 1010 L in the V band and hR ≈ 4 mathrmkpc. Show that the disk’s surface brightness at the Sun’s position, 8 kpc from the Galactic Center, is ∼ 20 L pc−2 . The mass density in the disk is 40 − 60 M pc−2 , so M/L ...
... that the disk’s total luminosity is LD = 2πh2R I(R = 0). For the Milky Way, LD ≈ 1.5 × 1010 L in the V band and hR ≈ 4 mathrmkpc. Show that the disk’s surface brightness at the Sun’s position, 8 kpc from the Galactic Center, is ∼ 20 L pc−2 . The mass density in the disk is 40 − 60 M pc−2 , so M/L ...
Ch 18
... much, so molecular gas clouds can be detected even though there may be other gas and dust clouds in the way. These clouds are mostly molecular hydrogen, which unfortunately does not emit in the radio portion of the spectrum. Other molecules present: CO, HCN, NH3, H2O, CH3OH, H2CO, and more than a hu ...
... much, so molecular gas clouds can be detected even though there may be other gas and dust clouds in the way. These clouds are mostly molecular hydrogen, which unfortunately does not emit in the radio portion of the spectrum. Other molecules present: CO, HCN, NH3, H2O, CH3OH, H2CO, and more than a hu ...
8.1 Radio Emission from Solar System objects
... from the hot ionized gas. In order to understand from which part of the sun’s atmosphere this emission arises, one needs to understand the main opacity source at radio wavelengths. (The opacity is a measure of how much a wave gets absorbed as it travels through a medium). The main source of opacity ...
... from the hot ionized gas. In order to understand from which part of the sun’s atmosphere this emission arises, one needs to understand the main opacity source at radio wavelengths. (The opacity is a measure of how much a wave gets absorbed as it travels through a medium). The main source of opacity ...
