P. Joss | Massachusetts Institute of Technology (MIT) (original) (raw)
Papers by P. Joss
Advances in Space Research, 2004
We present new results fitting Chandra ACIS and LETG/HRC-S spectra of the Cas A X-ray point sourc... more We present new results fitting Chandra ACIS and LETG/HRC-S spectra of the Cas A X-ray point source (XPS) and the isolated neutron star RX J1856.5-3754 to H, H-He, Si-ash, and Fe atmosphere models calculated with our compact atmosphere model code. In the case of the Cas A XPS, we find our atmosphere models fit significantly better than blackbody models, although a wide range of radii is formally permitted. The best fit H model is consistent with a neutron star of radius 7.6km,butwitharadiatingareascalesizeofonly7.6 km, but with a radiating area scale size of only 7.6km,butwitharadiatingareascalesizeofonly3 km, consistent with a hot spot geometry (discussed by, e.g. [Astrophys. J. Lett. 531 (2000) L53]). We also show the effects of the Cas A supernova remnant material on the XPS spectrum. In the case of RX J1856.5-3754 we find H and Fe spectra provide unacceptable fits to the X-ray and optical data, but we do find physically plausible results with a Si-ash model for a rapidly rotating neutron star.
Astronomy and Astrophysics, 1990
Monthly Notices of the Royal Astronomical Society, 1995
Supernovae, 1991
ABSTRACT Binary models are used to examine the possibility that the progenitor of SN 1987 is a co... more ABSTRACT Binary models are used to examine the possibility that the progenitor of SN 1987 is a component of a binary system. Certain ranges of parameter space in which binary evolution produces progenitors that are applicable to models of SN 1987A are considered. The proposed binary models are capable of making definite predictions that can be checked against observations.
The Astrophysical Journal, 1976
... Printed in USA THE TRANSIENT PERIODIC X-RAY SOURCE IN TAURUS, A0535+26* H. BRADT, W. MAYER, J... more ... Printed in USA THE TRANSIENT PERIODIC X-RAY SOURCE IN TAURUS, A0535+26* H. BRADT, W. MAYER, J. BUFF, GW CLARK, R. DOXSEY, D. HEARN, G. JERNIGAN, PC Joss, B. LAUFER, w. LEwIN, F. Li, T. MATILSKY, J. MCCLINTOCK, F. PRmnNI, S. RAPPAPORT,t ...
The Astrophysical Journal, 1976
... yield four celestial positions, each of which lies within 40" of the mean po... more ... yield four celestial positions, each of which lies within 40" of the mean position quoted above. A position obtained from Arid-S on Aug. 19 with a 3' error radius (Eyles et at. 1975a) lles 2 ~ 5 from the SAS-3 position. The importance of an optical or radio identification Time Bin FIG. ...
The Astrophysical Journal, 1976
... Printed in USA DISCOVERY OF A 283-SECOND PERIODIC VARIATION IN THE X-RAY SOURCE 3U 0900-40 JE... more ... Printed in USA DISCOVERY OF A 283-SECOND PERIODIC VARIATION IN THE X-RAY SOURCE 3U 0900-40 JE MCCLINTOCK, 5. RAPPAPORT,* PC Joss, H. BRADT, J. Bnr, GW CLARK, D. Hw~N, w. HG LEWIN, T. MATILSKY, W. MAYER, AND F. PiumNI Department of ...
Physics Reports, 1999
ABSTRACT The presence of a close binary companion can affect the evolution of a massive star thro... more ABSTRACT The presence of a close binary companion can affect the evolution of a massive star through one or more episodes of mass transfer, or by merger in a common-envelope phase. Monte Carlo calculations indicate that ∼20–35% of all massive supernovae are affected by such processes, and that a substantial fraction of these events will be supernovae of Type II. The properties of the progenitor star, the distribution of circumstellar material, the peak supernova luminosity, the shape of the supernova light curve, and other observable features of the supernova event can be affected by prior binary membership. Binary interactions may be the cause of much of the variability among Type II supernova light curves. In particular, many of the peculiarities of SN 1987A and SN 1993J may well have resulted from the prior duplicity of the progenitors.
Nature Physical Science, 1973
In support of the RAMOS (Russian American Observation Satellites) program, an ongoing series of f... more In support of the RAMOS (Russian American Observation Satellites) program, an ongoing series of flights is being conducted using FISTA (Flying Infrared Signatures Technology Aircraft) which, in part, carries instruments to obtain polarization measurements of solar radiation scattered from clouds. Spectral polarization measurements have been made simultaneously across the 2.5-3.5 μm region as a function of solar scattering angle using the Space Dynamics Laboratory's Hyperspectral imaging Polarimeter (HIP) instrument. The purpose of the experiment is to verify the expected strong sensitivity of polarization as a function of wavelengh within this spectral band, and to select the optimum wavelength for making remote diagnostic measurements of cloud compositions. There is also the complementary goal of studying polarization as a potential discriminator between naturally occurring solar-scatter backgrounds and man-made objects. Additional instrumentation onboard during these flights h...
We present Chandra ACIS and zeroth order HETG/ACIS-S spectra of the Cas A point source extracted ... more We present Chandra ACIS and zeroth order HETG/ACIS-S spectra of the Cas A point source extracted from a 50-ksec imaging and a 70-ksec grating observation of the Cas A supernova remnant. There is mounting evidence that the point source is a thermally emitting neutron star. We fit the ACIS spectra with the latest hydrogen / helium models produced by the
A short summary is given of Rappaport et al. (1983) which described results of extending a simpli... more A short summary is given of Rappaport et al. (1983) which described results of extending a simplified stellar evolution code covering the evolution of low-mass compact binaries. Magnetic braking is probably an important process in the evolution of such binaries (such as cataclysmic variables and low-mass X-ray sources). The initial simplified code describes the mass-losing star as an n = 3/2 polytrope and was developed to study the evolution of binaries with a secondary of low mass (between 0.01 and 0.4 solar mass) when the angular momentum losses are due to gravitational radiation. In the extended code, a composite polytrope model is used for the secondary, wherein the structure of the radiative core is described by an n = 3 polytrope and the convective envelope by an n = 3/2 polytrope.
The Astrophysical Journal, 1985
THE ASTROPHYSICAL JOURNAL, 295:98-103, 1985 August 1 © 1985. The American Astronomical Society. A... more THE ASTROPHYSICAL JOURNAL, 295:98-103, 1985 August 1 © 1985. The American Astronomical Society. All rights reserved. Printed in USA THE WIND-DISK INTERACTION IN X-RAY BURST SOURCES1 FuLvIo MELIA AND PAUL C. Joss Department of Physics, Center for Space ...
The helium-flash model for X-ray burst sources, in which matter is presumed to accrete onto the s... more The helium-flash model for X-ray burst sources, in which matter is presumed to accrete onto the surface of a neutron star, is discussed. Attention is given to the accretion process, nuclear burning, X-ray emission, and the energy released by convection as well as by radiative diffusion near the surface. The rise times of observed bursts, their spectral evolution, and the properties of the spectrally soft X-ray transients are considered. Problems in interpreting the continuum spectra are discussed, along with problems in the detection and measurement of line features in the spectra. Also considered are the ratio of time-averaged persistent luminosity to time-averaged burst luminosity, peak burst luminosities, and the possibility of detecting binary membership for burst sources.
RAMOS (Russian American Observational Satellites), scheduled for launch in 2009, is a joint missi... more RAMOS (Russian American Observational Satellites), scheduled for launch in 2009, is a joint mission of the Russian Federation and the United States of America. Two low earth-orbit satellites with complementary instrument suites will fly in tandem orbits at an altitude of ˜ 500 km and a variable mean separation of ˜ 300 km. The satellites will be capable of simultaneous viewing of the same location on or above the earth's surface, allowing for real-time stereoscopic imaging of the earth's environment. The sensors suite is composed of pointable multifiltered infrared (1.5 - 7.5 mu m), visible, and ultraviolet imaging radiometers. The nominal spatial footprints are ˜ 100 m at the earth's surface. One satellite will have polarization capability, and the other will have an infrared spectrometer built into the radiometer. During its projected two-year lifetime, RAMOS will be used as a testbed for a variety of space-based measurements of the terrestrial environment that requ...
The Astrophysical Journal, 1976
The Astrophysical Journal, 1976
The Astrophysical Journal, 1984
Advances in Space Research, 2004
We present new results fitting Chandra ACIS and LETG/HRC-S spectra of the Cas A X-ray point sourc... more We present new results fitting Chandra ACIS and LETG/HRC-S spectra of the Cas A X-ray point source (XPS) and the isolated neutron star RX J1856.5-3754 to H, H-He, Si-ash, and Fe atmosphere models calculated with our compact atmosphere model code. In the case of the Cas A XPS, we find our atmosphere models fit significantly better than blackbody models, although a wide range of radii is formally permitted. The best fit H model is consistent with a neutron star of radius 7.6km,butwitharadiatingareascalesizeofonly7.6 km, but with a radiating area scale size of only 7.6km,butwitharadiatingareascalesizeofonly3 km, consistent with a hot spot geometry (discussed by, e.g. [Astrophys. J. Lett. 531 (2000) L53]). We also show the effects of the Cas A supernova remnant material on the XPS spectrum. In the case of RX J1856.5-3754 we find H and Fe spectra provide unacceptable fits to the X-ray and optical data, but we do find physically plausible results with a Si-ash model for a rapidly rotating neutron star.
Astronomy and Astrophysics, 1990
Monthly Notices of the Royal Astronomical Society, 1995
Supernovae, 1991
ABSTRACT Binary models are used to examine the possibility that the progenitor of SN 1987 is a co... more ABSTRACT Binary models are used to examine the possibility that the progenitor of SN 1987 is a component of a binary system. Certain ranges of parameter space in which binary evolution produces progenitors that are applicable to models of SN 1987A are considered. The proposed binary models are capable of making definite predictions that can be checked against observations.
The Astrophysical Journal, 1976
... Printed in USA THE TRANSIENT PERIODIC X-RAY SOURCE IN TAURUS, A0535+26* H. BRADT, W. MAYER, J... more ... Printed in USA THE TRANSIENT PERIODIC X-RAY SOURCE IN TAURUS, A0535+26* H. BRADT, W. MAYER, J. BUFF, GW CLARK, R. DOXSEY, D. HEARN, G. JERNIGAN, PC Joss, B. LAUFER, w. LEwIN, F. Li, T. MATILSKY, J. MCCLINTOCK, F. PRmnNI, S. RAPPAPORT,t ...
The Astrophysical Journal, 1976
... yield four celestial positions, each of which lies within 40" of the mean po... more ... yield four celestial positions, each of which lies within 40" of the mean position quoted above. A position obtained from Arid-S on Aug. 19 with a 3' error radius (Eyles et at. 1975a) lles 2 ~ 5 from the SAS-3 position. The importance of an optical or radio identification Time Bin FIG. ...
The Astrophysical Journal, 1976
... Printed in USA DISCOVERY OF A 283-SECOND PERIODIC VARIATION IN THE X-RAY SOURCE 3U 0900-40 JE... more ... Printed in USA DISCOVERY OF A 283-SECOND PERIODIC VARIATION IN THE X-RAY SOURCE 3U 0900-40 JE MCCLINTOCK, 5. RAPPAPORT,* PC Joss, H. BRADT, J. Bnr, GW CLARK, D. Hw~N, w. HG LEWIN, T. MATILSKY, W. MAYER, AND F. PiumNI Department of ...
Physics Reports, 1999
ABSTRACT The presence of a close binary companion can affect the evolution of a massive star thro... more ABSTRACT The presence of a close binary companion can affect the evolution of a massive star through one or more episodes of mass transfer, or by merger in a common-envelope phase. Monte Carlo calculations indicate that ∼20–35% of all massive supernovae are affected by such processes, and that a substantial fraction of these events will be supernovae of Type II. The properties of the progenitor star, the distribution of circumstellar material, the peak supernova luminosity, the shape of the supernova light curve, and other observable features of the supernova event can be affected by prior binary membership. Binary interactions may be the cause of much of the variability among Type II supernova light curves. In particular, many of the peculiarities of SN 1987A and SN 1993J may well have resulted from the prior duplicity of the progenitors.
Nature Physical Science, 1973
In support of the RAMOS (Russian American Observation Satellites) program, an ongoing series of f... more In support of the RAMOS (Russian American Observation Satellites) program, an ongoing series of flights is being conducted using FISTA (Flying Infrared Signatures Technology Aircraft) which, in part, carries instruments to obtain polarization measurements of solar radiation scattered from clouds. Spectral polarization measurements have been made simultaneously across the 2.5-3.5 μm region as a function of solar scattering angle using the Space Dynamics Laboratory's Hyperspectral imaging Polarimeter (HIP) instrument. The purpose of the experiment is to verify the expected strong sensitivity of polarization as a function of wavelengh within this spectral band, and to select the optimum wavelength for making remote diagnostic measurements of cloud compositions. There is also the complementary goal of studying polarization as a potential discriminator between naturally occurring solar-scatter backgrounds and man-made objects. Additional instrumentation onboard during these flights h...
We present Chandra ACIS and zeroth order HETG/ACIS-S spectra of the Cas A point source extracted ... more We present Chandra ACIS and zeroth order HETG/ACIS-S spectra of the Cas A point source extracted from a 50-ksec imaging and a 70-ksec grating observation of the Cas A supernova remnant. There is mounting evidence that the point source is a thermally emitting neutron star. We fit the ACIS spectra with the latest hydrogen / helium models produced by the
A short summary is given of Rappaport et al. (1983) which described results of extending a simpli... more A short summary is given of Rappaport et al. (1983) which described results of extending a simplified stellar evolution code covering the evolution of low-mass compact binaries. Magnetic braking is probably an important process in the evolution of such binaries (such as cataclysmic variables and low-mass X-ray sources). The initial simplified code describes the mass-losing star as an n = 3/2 polytrope and was developed to study the evolution of binaries with a secondary of low mass (between 0.01 and 0.4 solar mass) when the angular momentum losses are due to gravitational radiation. In the extended code, a composite polytrope model is used for the secondary, wherein the structure of the radiative core is described by an n = 3 polytrope and the convective envelope by an n = 3/2 polytrope.
The Astrophysical Journal, 1985
THE ASTROPHYSICAL JOURNAL, 295:98-103, 1985 August 1 © 1985. The American Astronomical Society. A... more THE ASTROPHYSICAL JOURNAL, 295:98-103, 1985 August 1 © 1985. The American Astronomical Society. All rights reserved. Printed in USA THE WIND-DISK INTERACTION IN X-RAY BURST SOURCES1 FuLvIo MELIA AND PAUL C. Joss Department of Physics, Center for Space ...
The helium-flash model for X-ray burst sources, in which matter is presumed to accrete onto the s... more The helium-flash model for X-ray burst sources, in which matter is presumed to accrete onto the surface of a neutron star, is discussed. Attention is given to the accretion process, nuclear burning, X-ray emission, and the energy released by convection as well as by radiative diffusion near the surface. The rise times of observed bursts, their spectral evolution, and the properties of the spectrally soft X-ray transients are considered. Problems in interpreting the continuum spectra are discussed, along with problems in the detection and measurement of line features in the spectra. Also considered are the ratio of time-averaged persistent luminosity to time-averaged burst luminosity, peak burst luminosities, and the possibility of detecting binary membership for burst sources.
RAMOS (Russian American Observational Satellites), scheduled for launch in 2009, is a joint missi... more RAMOS (Russian American Observational Satellites), scheduled for launch in 2009, is a joint mission of the Russian Federation and the United States of America. Two low earth-orbit satellites with complementary instrument suites will fly in tandem orbits at an altitude of ˜ 500 km and a variable mean separation of ˜ 300 km. The satellites will be capable of simultaneous viewing of the same location on or above the earth's surface, allowing for real-time stereoscopic imaging of the earth's environment. The sensors suite is composed of pointable multifiltered infrared (1.5 - 7.5 mu m), visible, and ultraviolet imaging radiometers. The nominal spatial footprints are ˜ 100 m at the earth's surface. One satellite will have polarization capability, and the other will have an infrared spectrometer built into the radiometer. During its projected two-year lifetime, RAMOS will be used as a testbed for a variety of space-based measurements of the terrestrial environment that requ...
The Astrophysical Journal, 1976
The Astrophysical Journal, 1976
The Astrophysical Journal, 1984