Molecular Gas in the Large Magellanic Cloud
... At the Centre for Astrophysics and Supercomputing, I am especially grateful to Matthew Bailes, who convinced me to move to Melbourne and introduced me to astronomy research while I was still a first-year undergraduate. The Centre will be hard-pressed to find a Director who promotes and advocates for s ...
... At the Centre for Astrophysics and Supercomputing, I am especially grateful to Matthew Bailes, who convinced me to move to Melbourne and introduced me to astronomy research while I was still a first-year undergraduate. The Centre will be hard-pressed to find a Director who promotes and advocates for s ...
Binary and Millisecond Pulsars | SpringerLink
... Pulsars are weak radio sources. Measured intensities at 1.4 GHz vary between 5µJy and 1 Jy (1 Jy ≡ 10−26 W m−2 Hz−1 ). As a result, even with a large radio telescope, the coherent addition of many hundreds or even thousands of pulses is usually required in order to produce a detectable “integrated p ...
... Pulsars are weak radio sources. Measured intensities at 1.4 GHz vary between 5µJy and 1 Jy (1 Jy ≡ 10−26 W m−2 Hz−1 ). As a result, even with a large radio telescope, the coherent addition of many hundreds or even thousands of pulses is usually required in order to produce a detectable “integrated p ...
The empirical grounds of SN
... We have caught a SN in the act of exploding (about 100s after the collapse of the core) We have definitely proved that SN and GRB are coeval events We have measured the radius of the progenitor star, to be about 4 x 1011 cm which is typical of a W-R star. ...
... We have caught a SN in the act of exploding (about 100s after the collapse of the core) We have definitely proved that SN and GRB are coeval events We have measured the radius of the progenitor star, to be about 4 x 1011 cm which is typical of a W-R star. ...
https://tel.archives-ouvertes.fr/file/index/docid/1058049/filename/HOU_XIAN_2013.pdf
... year of my thesis and in my job hunting, though we haven’t really chatted much in the real world, incredible! I will not forget to express my appreciation to the Pulsar Timing Consortium which has generously provided radio ephemerides for pulsars without which my detections of gamma-ray pulsars woul ...
... year of my thesis and in my job hunting, though we haven’t really chatted much in the real world, incredible! I will not forget to express my appreciation to the Pulsar Timing Consortium which has generously provided radio ephemerides for pulsars without which my detections of gamma-ray pulsars woul ...
11115002
... Regardless of the changing shape, the jet as a whole can be seen to be of a welldefined shape that is called the envelope, though initially is narrow and only pointing towards the pulsar’s proper motion, gradually bends the opposite way at greater distances from the pulsar. The brighter inner jet do ...
... Regardless of the changing shape, the jet as a whole can be seen to be of a welldefined shape that is called the envelope, though initially is narrow and only pointing towards the pulsar’s proper motion, gradually bends the opposite way at greater distances from the pulsar. The brighter inner jet do ...
Discovery and Study of Exotic Radio Pulsars Jason William Thomas
... characteristics of the globular cluster pulsar population in general, particularly the luminosity function. In observations of the rich, massive cluster Terzan 5 with the Green Bank Telescope we have discovered the 1.396-ms pulsar J1748−2446ad, which is now the fastest-spinning neutron star known. T ...
... characteristics of the globular cluster pulsar population in general, particularly the luminosity function. In observations of the rich, massive cluster Terzan 5 with the Green Bank Telescope we have discovered the 1.396-ms pulsar J1748−2446ad, which is now the fastest-spinning neutron star known. T ...
The effect of stellar limb darkening values on the accuracy of the
... Some modellers fix the limb darkening coefficients according to these or other tables when they fit a transit curve. As is clear from the aforementioned discrepancies, in some temperature regions this is not a good strategy because the values of the limb darkening coefficients are not consistent and ...
... Some modellers fix the limb darkening coefficients according to these or other tables when they fit a transit curve. As is clear from the aforementioned discrepancies, in some temperature regions this is not a good strategy because the values of the limb darkening coefficients are not consistent and ...
Document
... T Tau Sb - (I’d like to Get Rid of Sb…) but there’s NO Ejection! • Radio data referenced to the moving IR position of T Tau S shows NO evidence for an ejection event! • Perhaps more importantly, IR and radio positions for T Tau Sb don’t coincide for data from 2001 (differ by ~40mas) ...
... T Tau Sb - (I’d like to Get Rid of Sb…) but there’s NO Ejection! • Radio data referenced to the moving IR position of T Tau S shows NO evidence for an ejection event! • Perhaps more importantly, IR and radio positions for T Tau Sb don’t coincide for data from 2001 (differ by ~40mas) ...
PhD thesis
... 6 IRAS 19035+0641: a compact radio source embedded in 6.1 General overview . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Observations . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.1 Very Large Array . . . . . . . . . . . . . . . . . . . 6.3 Continuum results . . . . . . . . . . . . . ...
... 6 IRAS 19035+0641: a compact radio source embedded in 6.1 General overview . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Observations . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.1 Very Large Array . . . . . . . . . . . . . . . . . . . 6.3 Continuum results . . . . . . . . . . . . . ...
Physics of Neutron Star Crusts
... is expected to be very different from that formed during the aftermath of a supernova explosion. We show how it can be a site for nuclear reactions. We study its thermal structure during accretion, and briefly review the phenomenon of X-ray bursts. We quantitatively analyze the phenomenon of deep cru ...
... is expected to be very different from that formed during the aftermath of a supernova explosion. We show how it can be a site for nuclear reactions. We study its thermal structure during accretion, and briefly review the phenomenon of X-ray bursts. We quantitatively analyze the phenomenon of deep cru ...
Physics of Neutron Star Crusts - Institut d`Astronomie et d
... neutron superfluidity, considering first a uniform neutron gas, and then discussing the effects of the presence of the nuclear crystal lattice. In the following, we consider the superfluid hydrodynamics. We stress those points, which have been raised only recently. We consider also the important problem ...
... neutron superfluidity, considering first a uniform neutron gas, and then discussing the effects of the presence of the nuclear crystal lattice. In the following, we consider the superfluid hydrodynamics. We stress those points, which have been raised only recently. We consider also the important problem ...
Thesis (complete) - Research Explorer
... evolutionary stage of these stars remained unclear. After the discovery of the hydrogen burning processes, the pp-reaction and the CNO-cycle, that provide energy to stars during the main sequence (Bethe 1939), models that reproduced and explained the stellar structure in this phase quickly developed ...
... evolutionary stage of these stars remained unclear. After the discovery of the hydrogen burning processes, the pp-reaction and the CNO-cycle, that provide energy to stars during the main sequence (Bethe 1939), models that reproduced and explained the stellar structure in this phase quickly developed ...
The Hunt for Recoiled Black Holes in the Milky Way`s
... Because all galaxies in the universe contain central black holes, during galaxy mergers, the central black holes must merge as well. According to Volonteri & Perna (2005), when coalescing black holes emit gravitational waves asymmetrically, to conserve momentum, the system ejects one black hole from ...
... Because all galaxies in the universe contain central black holes, during galaxy mergers, the central black holes must merge as well. According to Volonteri & Perna (2005), when coalescing black holes emit gravitational waves asymmetrically, to conserve momentum, the system ejects one black hole from ...
Watson et al. 2007a - Department of Physics and Astronomy
... devise. We began with the Spitzer Science Center IRS data pipeline, v. S13.2: the Basic Calibrated Data (BCD) product for low-resolution spectra, and the non-flatfielded “droop” product for high resolution. Permanently-bad detector pixels, and “rogue” pixels for which responsivity and noise are stro ...
... devise. We began with the Spitzer Science Center IRS data pipeline, v. S13.2: the Basic Calibrated Data (BCD) product for low-resolution spectra, and the non-flatfielded “droop” product for high resolution. Permanently-bad detector pixels, and “rogue” pixels for which responsivity and noise are stro ...
kdtalk_jun2005 - The HST Treasury Program on Eta Carinae
... Initial mass 140 to 200 M sun , Present-day mass 110 to 150 M sun . 2. Most extreme stellar wind. Mass-loss rate is around 0.001 M sun per year. That’s 300 to 1000 more than a normal massive star. ...
... Initial mass 140 to 200 M sun , Present-day mass 110 to 150 M sun . 2. Most extreme stellar wind. Mass-loss rate is around 0.001 M sun per year. That’s 300 to 1000 more than a normal massive star. ...
Radiation-driven wind models of massive stars
... dynamical role, as they are responsible for a large amount of momentum and energy input into the ISM due to stellar winds and supernova explosions. See Abbott (1982b) and Leitherer et al. (1992) for an overview. Moreover, as massive stars are hot, with effective temperatures in the range of about 10 ...
... dynamical role, as they are responsible for a large amount of momentum and energy input into the ISM due to stellar winds and supernova explosions. See Abbott (1982b) and Leitherer et al. (1992) for an overview. Moreover, as massive stars are hot, with effective temperatures in the range of about 10 ...
Formation and evolution of giant molecular clouds in a barred spiral
... Understanding where and how gas is converted into stars in a galaxy is important for understanding a galaxy’s formation and evolution through each epoch of the universe. Which physical processes control the star formation in a galaxy is heavily debated. We are now at a stage where it is possible to ...
... Understanding where and how gas is converted into stars in a galaxy is important for understanding a galaxy’s formation and evolution through each epoch of the universe. Which physical processes control the star formation in a galaxy is heavily debated. We are now at a stage where it is possible to ...
Revising the census of low luminosity AGN
... ONLY A FEW PERCENT! MOST OF THEM HAVE LOW EW AND ARE UNLIKELY TO BE AGN THE LINE EMISSION IS PRODUCED BY THE HOST GALAXY, NOT BY THE AGN THE LINERs REGION IS MOSTLY POPULATED BY NON-AGN THE EW IS A BEST PREDICTOR FOR GENUINE AGN THAN THE DIAGNOSTIC DIAGRAMS A LOW EW (~1 Å) IS CHARACTERISTIC OF STELL ...
... ONLY A FEW PERCENT! MOST OF THEM HAVE LOW EW AND ARE UNLIKELY TO BE AGN THE LINE EMISSION IS PRODUCED BY THE HOST GALAXY, NOT BY THE AGN THE LINERs REGION IS MOSTLY POPULATED BY NON-AGN THE EW IS A BEST PREDICTOR FOR GENUINE AGN THAN THE DIAGNOSTIC DIAGRAMS A LOW EW (~1 Å) IS CHARACTERISTIC OF STELL ...
http://arxiv.org/pdf/1401.1510v1.pdf
... Thomas et al. 2005). Several authors have pointed out that sub-millimeter galaxies (SMGs) may be examples of the above scenario (e.g. Blain et al. 2004; Chapman et al. 2005; Tacconi et al. 2006; Toft et al. 2007; Cimatti et al. 2008; Capak et al. 2008; Tacconi et al. 2008; Schinnerer et al. 2008; Co ...
... Thomas et al. 2005). Several authors have pointed out that sub-millimeter galaxies (SMGs) may be examples of the above scenario (e.g. Blain et al. 2004; Chapman et al. 2005; Tacconi et al. 2006; Toft et al. 2007; Cimatti et al. 2008; Capak et al. 2008; Tacconi et al. 2008; Schinnerer et al. 2008; Co ...
Cygnus X-1
Cygnus X-1 (abbreviated Cyg X-1) is a well-known galactic X-ray source, thought to be a black hole, in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 6977229999999999999♠2.3×10−23 Wm−2 Hz−1 (7003230000000000000♠2.3×103 Jansky). Cygnus X-1 was the first X-ray source widely accepted to be a black hole and it remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any known kind of normal star, or other likely object besides a black hole. If so, the radius of its event horizon is about 7004440000000000000♠44 km.Cygnus X-1 belongs to a high-mass X-ray binary system about 7019574266339685654♠6070 ly from the Sun that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicular to the disk, are carrying part of the energy of the infalling material away into interstellar space.This system may belong to a stellar association called Cygnus OB3, which would mean that Cygnus X-1 is about five million years old and formed from a progenitor star that had more than 7001400000000000000♠40 solar masses. The majority of the star's mass was shed, most likely as a stellar wind. If this star had then exploded as a supernova, the resulting force would most likely have ejected the remnant from the system. Hence the star may have instead collapsed directly into a black hole.Cygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.