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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
The Mass Of The Black Hole In The Seyfert 1 Galaxy Ngc 4593 From Reverberation Mapping, Kelly D. Denney, Misty C. Bentz, Bradley M. Peterson, Richard W. Pogge, Edward M. Cackett, Matthias Dietrich, Jeffrey K. J. Fogel, Himel Ghosh, Keith D. Horne, Charles Kuehn, Takeo Minezaki, Christopher A. Onken, Vladimir I. Pronik, Douglas O. Richstone, Sergey G. Sergeev, Marianne Vestergaard, Matthew G. Walker, Yuzuru Yoshii
The Mass Of The Black Hole In The Seyfert 1 Galaxy Ngc 4593 From Reverberation Mapping, Kelly D. Denney, Misty C. Bentz, Bradley M. Peterson, Richard W. Pogge, Edward M. Cackett, Matthias Dietrich, Jeffrey K. J. Fogel, Himel Ghosh, Keith D. Horne, Charles Kuehn, Takeo Minezaki, Christopher A. Onken, Vladimir I. Pronik, Douglas O. Richstone, Sergey G. Sergeev, Marianne Vestergaard, Matthew G. Walker, Yuzuru Yoshii
Physics and Astronomy Faculty Research Publications
We present new observations leading to an improved black hole mass estimate for the Seyfert 1 galaxy NGC 4593 as part of a reverberation-mapping campaign conducted at the MDM Observatory. Cross-correlation analysis of the Hβ emission-line light curve with the optical continuum light curve reveals an emission-line time delay of τcent=3.73+/-0.75 days. By combining this time delay with the Hβ line width, we derive a central black hole mass of MBH=(9.8+/-2.1)×106 Msolar, an improvement in precision of a factor of several over past results.
The Asymmetric Explosion Of Type Ia Supernovae As Seen From Near-Infrared Observations, Kentaro Motohara, Keiichi Maeda, Christopher L. Gerardy, Ken'ichi Nomoto, Masaomi Tanaka, Nozomu Tominaga, Takuya Ohkubo, Paolo A. Mazzali, Robert A. Fesen, Peter Hoflich, J. Craig Wheeler
The Asymmetric Explosion Of Type Ia Supernovae As Seen From Near-Infrared Observations, Kentaro Motohara, Keiichi Maeda, Christopher L. Gerardy, Ken'ichi Nomoto, Masaomi Tanaka, Nozomu Tominaga, Takuya Ohkubo, Paolo A. Mazzali, Robert A. Fesen, Peter Hoflich, J. Craig Wheeler
Dartmouth Scholarship
We present near-infrared spectra of late-phase (>200 days) Type Ia supernovae (SNe Ia) taken at the Subaru Telescope. The [Fe II] line of SN 2003hv shows a clear flat-topped feature, while that of SN 2005W shows a less prominent flatness. In addition, a large shift in their line center, varying from -3000 to 1000 km s-1 with respect to the host galaxies, is seen. Such a shift suggests the occurrence of an off-center, nonspherical explosion in the central region and provides important, new constraints on the explosion models of SNe Ia.
Spitzer Measurements Of Atomic And Molecular Abundances In The Type Iip Sn 2005af, Rubina Kotak, Peter Meikle, Monica Pozzo, Schuyler D. Van Dyk, Duncan Farrah, Robert Fesen, Alexei V. Filippenko, Ryan J. Foley, Claes Fransson, Christopher L. Gerardy, Peter A. Hoflich, Peter Lundqvist, Seppo Mattila, Jesper Sollerman, J. Craig Wheeler
Spitzer Measurements Of Atomic And Molecular Abundances In The Type Iip Sn 2005af, Rubina Kotak, Peter Meikle, Monica Pozzo, Schuyler D. Van Dyk, Duncan Farrah, Robert Fesen, Alexei V. Filippenko, Ryan J. Foley, Claes Fransson, Christopher L. Gerardy, Peter A. Hoflich, Peter Lundqvist, Seppo Mattila, Jesper Sollerman, J. Craig Wheeler
Dartmouth Scholarship
We present results based on mid-infrared (3.6-30 μm) observations with the Spitzer Space Telescope of the nearby Type IIP supernova 2005af. We report the first ever detection of the SiO molecule in a Type IIP supernova. Together with the detection of the CO fundamental, this is an exciting finding as it may signal the onset of dust condensation in the ejecta. From a wealth of fine-structure lines we provide abundance estimates for stable Ni, Ar, and Ne that, via spectral synthesis, may be used to constrain nucleosynthesis models.
Cooling Of The Quasi-Persistent Neutron Star X-Ray Transients Ks 1731-260 And Mxb 1659-29, Edward M. Cackett, Rudy Wijnands, Manuel Linares, Jon M. Miller, Jeroen Homan, Walter H. G. Lewin
Cooling Of The Quasi-Persistent Neutron Star X-Ray Transients Ks 1731-260 And Mxb 1659-29, Edward M. Cackett, Rudy Wijnands, Manuel Linares, Jon M. Miller, Jeroen Homan, Walter H. G. Lewin
Physics and Astronomy Faculty Research Publications
We present Chandra and XMM-Newton X-ray observations that monitor the neutron star cooling of the quasi-persistent neutron star X-ray transients KS 1731-260 and MXB 1659-29 for approximately 4 yr after these sources returned to quiescence from prolonged outbursts. In both sources the outbursts were long enough to significantly heat the neutron star crust out of thermal equilibrium with the core. We analyse the X-ray spectra by fitting absorbed neutron star atmosphere models to the observations. The results of our analysis strengthen the preliminary findings of Wijnands et al. that in both sources the neutron star crust cools down very rapidly …
Xmm-Newton Discovery Of The X-Ray Transient Xmmu J181227.8-181234 In The Galactic Plane, Edward M. Cackett, Rudy Wijnands, Ron Remillard
Xmm-Newton Discovery Of The X-Ray Transient Xmmu J181227.8-181234 In The Galactic Plane, Edward M. Cackett, Rudy Wijnands, Ron Remillard
Physics and Astronomy Faculty Research Publications
We report the discovery of an X-ray transient, observed in outburst with XMM-Newton on 2003 March 20, and with position (J2000, approximate positional error 2arcsec). No known source is present at this position and the source was not detected during published ROSAT or ASCA observations of that region. However, the source may be associated with 1H1812-182 detected by HEAO 1, although the error bars on the HEAO 1 position are very large and the two sources could also be unrelated. Therefore, we name the source XMMU J181227.8-181234. Initially, the source was not detected using the All-Sky Monitor (ASM) on-board the …
A Chandra X-Ray Observation Of The Globular Cluster Terzan 1, E. M. Cackett, R. Wijnands, C. O. Heinke, D. Pooley, W. H. G. Lewin, J. E. Grindlay, P. D. Edmonds, P. G. Jonker, J. M. Miller
A Chandra X-Ray Observation Of The Globular Cluster Terzan 1, E. M. Cackett, R. Wijnands, C. O. Heinke, D. Pooley, W. H. G. Lewin, J. E. Grindlay, P. D. Edmonds, P. G. Jonker, J. M. Miller
Physics and Astronomy Faculty Research Publications
We present a ~19-ks Chandra Advanced CCD Imaging Spectrometer (ACIS)-S observation of the globular cluster Terzan 1. 14 sources are detected within 1.4arcmin of the cluster centre with two of these sources predicted to be not associated with the cluster (background active galactic nuclei or foreground objects). The neutron star X-ray transient, X1732-304, has previously been observed in outburst within this globular cluster with the outburst seen to last for at least 12yr. Here, we find four sources that are consistent with the ROSAT position for this transient, but none of the sources are fully consistent with the position of …
Photoionized HΒ Emission In Ngc 5548: It Breathes!, Edward M. Cackett, Keith Horne
Photoionized HΒ Emission In Ngc 5548: It Breathes!, Edward M. Cackett, Keith Horne
Physics and Astronomy Faculty Research Publications
Emission-line regions in active galactic nuclei (AGNs) and other photoionized nebulae should become larger in size when the ionizing luminosity increases. This `breathing' effect is observed for the Hβ emission in NGC 5548 by using Hβ and optical continuum light curves from the 13-yr (1989-2001) AGN Watch monitoring campaign. To model the breathing, we use two methods to fit the observed light curves in detail: (i) parametrized models and, (ii) the MEMECHO reverberation-mapping code. Our models assume that optical continuum variations track the ionizing radiation, and that the Hβ variations respond with time-delays τ due to light travel-time. By fitting …