Mohan Ganeshalingam

An Unusually Fast-Evolving Supernova (2009)

Poznanski, Dovi, Chornock, Ryan, Nugent, Peter E., Bloom, Joshua S., Ganeshalingam, Mohan, Leonard, Douglas C., ...

Analyses of supernovae (SNe) have revealed two main types of progenitors: exploding white dwarfs and collapsing massive stars. We present SN2002bj, which stands out as different from any SN reported...

Variable Sodium Absorption in a Low-extinction Type Ia Supernova (2009)

Simon, Joshua D., Gal-Yam, Avishay, Gnat, Orly, Quimby, Robert M., Ganeshalingam, Mohan, Silverman, Jeffrey M., ...

Recent observations have revealed that some Type Ia supernovae exhibit narrow, time-variable Na I D absorption features. The origin of the absorbing material is controversial, but it may suggest the...

The Lick AGN Monitoring Project: Broad-Line Region Radii and Black Hole Masses from Reverberation Mapping of Hbeta (2009)

Bentz, Misty C., Walsh, Jonelle L., Barth, Aaron J., Baliber, Nairn, Bennert, Nicola, Canalizo, Gabriela, ...

We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with the aim of measuring the masses of the black holes in 12 nearby (z < 0.05)...

Variable Sodium Absorption in a Low-Extinction Type Ia Supernova (2009)

Simon, Joshua D., Gal-Yam, Avishay, Gnat, Orly, Quimby, Robert M., Ganeshalingam, Mohan, Silverman, Jeffrey M., ...

Recent observations have revealed that some Type Ia supernovae exhibit narrow, time-variable Na I D absorption features. The origin of the absorbing material is controversial, but it may suggest the...

Optical Spectroscopy of the Somewhat Peculiar Type IIb Supernova 2001ig (2009)

Silverman, Jeffrey M., Mazzali, Paolo, Chornock, Ryan, Filippenko, Alexei V., Clocchiatti, Alejandro, Phillips, Mark M., ...

Here we present previously unpublished optical spectra of supernova (SN) 2001ig, a Type IIb SN, from about a week after explosion until nearly one year later. The earliest spectrum consists of only a...

SN 2008ha: An Extremely Low Luminosity and Extremely Low Energy Supernova (2009)

Foley, Ryan J., Chornock, Ryan, Filippenko, Alexei V., Ganeshalingam, Mohan, Kirshner, Robert P., Li, Weidong, ...

We present ultraviolet, optical, and near-infrared photometry as well as optical spectra of the peculiar supernova (SN) 2008ha. SN 2008ha had a very low peak luminosity, reaching only M_V = -14.2...

SN 2008S: A Cool Super-Eddington Wind in a Supernova Impostor (2008)

Smith, Nathan, Ganeshalingam, Mohan, Li, Weidong, Chornock, Ryan, Steele, Thea N., Silverman, Jeffrey M., ...

We present visual-wavelength photometry and spectroscopy of SN2008S. Based on the relatively low peak luminosity for a supernova (SN) of M_R = -13.9 mag and moderate outflow speeds of \la 600 km/s...

Improved Standardization of Type II-P Supernovae: Application to an Expanded Sample (2008)

Poznanski, Dovi, Butler, Nathaniel, Filippenko, Alexei V., Ganeshalingam, Mohan, Li, Weidong, Bloom, Joshua S., ...

In the epoch of precise and accurate cosmology, cross-confirmation using a variety of cosmographic methods is paramount to circumvent systematic uncertainties. Owing to progenitor histories and...

First Results from the Lick AGN Monitoring Project: The Mass of the Black Hole in Arp 151 (2008)

Bentz, Misty C., Walsh, Jonelle L., Barth, Aaron J., Baliber, Nairn, Bennert, Nicola, Canalizo, Gabriela, ...

We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with the aim of measuring the masses of the black holes in 13 nearby (z < 0.05)...

Coronal lines and dust formation in SN 2005ip: Not the brightest, but the hottest Type IIn supernova (2008)

Smith, Nathan, Silverman, Jeffrey M., Chornock, Ryan, Filippenko, Alexei V., Wang, Xiaofeng, Li, Weidong, ...

We present optical photometry and spectroscopy of SN2005ip for the first 3yr after discovery, showing an underlying Type II-L SN interacting with a steady wind to yield an unusual Type IIn spectrum....

SN 2006tf: Precursor Eruptions and the Optically Thick Regime of Extremely Luminous Type IIn Supernovae (2008)

Smith, Nathan, Chornock, Ryan, Li, Weidong, Ganeshalingam, Mohan, Silverman, Jeffrey M., Foley, Ryan J., ...

SN2006tf is the third most luminous SN discovered so far, after SN2005ap and SN2006gy. SN2006tf is valuable because it provides a link between two regimes: (1) luminous type IIn supernovae powered by...

Optical and Near-Infrared Observations of the Highly Reddened, Rapidly Expanding Type Ia Supernova 2006X in M100 (2007)

Wang, Xiaofeng, Li, Weidong, Filippenko, Alexei V., Krisciunas, Kevin, Suntzeff, Nicholas B., Li, Junzheng, ...

We present extensive optical (UBVRI), near-infrared (JK) light curves and optical spectroscopy of the Type Ia supernova (SN) 2006X in the nearby galaxy NGC 4321 (M100). Our observations suggest that...

SN 2006jc: A Wolf-Rayet Star Exploding in a Dense He-Rich Circumstellar Medium (2006)

Foley, Ryan J., Smith, Nathan, Ganeshalingam, Mohan, Li, Weidong, Chornock, Ryan, Filippenko, Alexei V.

We present optical photometry and spectra of the peculiar Type Ib supernova (SN) 2006jc. Strong and relatively narrow He I emission lines indicate the progenitor star exploded inside a dense...

Multiwavelength Monitoring of the Dwarf Seyfert 1 Galaxy NGC 4395. III. Optical Variability and X-ray/UV/Optical Correlations (2006)

Desroches, Louis-Benoit, Filippenko, Alexei V., Kaspi, Shai, Laor, Ari, Maoz, Dan, Ganeshalingam, Mohan, ...

We present optical observations of the low-luminosity Seyfert 1 nucleus of NGC 4395, as part of a multiwavelength reverberation-mapping program. Observations were carried out over two nights in 2004...

A non-spherical core in the explosion of supernova SN 2004dj (2006)

Leonard, Douglas C., Filippenko, Alexei V., Ganeshalingam, Mohan, Serduke, Franklin J. D., Li, Weidong, Swift, Brandon J., ...

An important and perhaps critical clue to the mechanism driving the explosion of massive stars as supernovae is provided by the accumulating evidence for asymmetry in the explosion. Indirect evidence...