SN 2003bg: The First Type IIb Hypernova (2009)
Hamuy, Mario, Deng, Jinsong, Mazzali, Paolo A., Morrell, Nidia I., Phillips, Mark M., Roth, Miguel, ...
Optical and near-infrared photometry and optical spectroscopy are reported for SN 2003bg, starting a few days after explosion and extending for a period of more than 300 days. Our early-time spectra...
GRB 090426: The Environment of a Rest-Frame 0.35-second Gamma-Ray Burst at Redshift z=2.609 (2009)
Levesque, Emily M., Bloom, Joshua S., Butler, Nathaniel R., Perley, Daniel A., Cenko, S. Bradley, Prochaska, J. Xavier, ...
We present the discovery of an absorption-line redshift of z = 2.609 for GRB 090426, establishing the first firm lower limit to a redshift for a gamma-ray burst with an observed duration of 90%...
Spectral Evolution of the Extraordinary Type IIn Supernova 2006gy (2009)
Smith, Nathan, Chornock, Ryan, Silverman, Jeffrey M., Filippenko, Alexei V., Foley, Ryan J.
We present a detailed analysis of the extremely luminous Type IIn supernova SN2006gy using spectra obtained between days 36 and 237 after explosion. We derive the temporal evolution of the effective...
The Quasar SDSS J1536+0441: An Unusual Double-Peaked Emitter (2009)
Chornock, Ryan, Bloom, J. S., Cenko, S. B., Filippenko, A. V., Silverman, J. M., Hicks, M. D., ...
The quasar SDSS J153636.22+044127.0, exhibiting peculiar broad emission-line profiles with multiple components, was proposed as a candidate sub-parsec binary supermassive black hole system. More...
Riess, Adam G., Macri, Lucas, Casertano, Stefano, Sosey, Megan, Lampeitl, Hubert, Ferguson, Henry C., ...
We report observations of 240 Cepheid variables obtained with the Near Infrared Camera (NICMOS) through the F160W filter on the Hubble Space Telescope (HST). The Cepheids are distributed across six...
Cepheid Calibrations of Modern Type Ia Supernovae:Implications for the Hubble Constant (2009)
Riess, Adam G., Macri, Lucas, Li, Weidong, Lampeitl, Hubert, Casertano, Stefano, Ferguson, Henry C., ...
This is the first of two papers reporting measurements from a program to determine the Hubble constant to 5% precision from a refurbished distance ladder. We present new observations of 110 Cepheid...
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Here we present previously unpublished optical spectra of supernova (SN) 2001ig, a Type IIb SN, from about a week after explosion until nearly one year later.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...
O/IR Polarimetry for the 2010 Decade (SSE): Science at the Edge, Sharp Tools for All (2009)
Hoffman, Jennifer L., Hines, Dean C., Adamson, Andy, Bjorkman, Karen, Chornock, Ryan, ...
Science opportunities and recommendations concerning optical/infrared polarimetry for the upcoming decade in the fields of stars and stellar evolution. Community-based White Paper to Astro2010 in...
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...
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., ...
Supernova 2003bg: the first type IIb hypernova (2009)
Hamuy, Mario, Deng, Jinsong, Mazzali, Paolo A., Morrell, Nidia I., Phillips, Mark M., Roth, Miguel, ...
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...
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....
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...
Chemical Abundances of the Secondary Star in the Black Hole X-ray Binary XTE J1118+480 (2008)
Hernández, Jonay I. González, Rebolo, Rafael, Israelian, Garik, Filippenko, Alexei V., Chornock, Ryan, Tominaga, Nozomu, ...
Following the recent abundance measurements of Mg, Al, Ca, Fe, and Ni in the black hole X-ray binary XTE J1118+480 using medium-resolution Keck II/ESI spectra of the secondary star (Gonz\'alez...
The Dual-Axis Circumstellar Environment of the Type IIn Supernova 1997eg (2007)
Hoffman, Jennifer L., Leonard, Douglas C., Chornock, Ryan, Filippenko, Alexei V., Barth, Aaron J., Matheson, Thomas
We present multi-epoch spectral and spectropolarimetric observations of the Type IIn supernova (SN) 1997eg that indicate the presence of a flattened disk-like concentration of circumstellar material...
The peculiar SN 2005hk: Do some type Ia supernovae explode as deflagrations? (2007)
Phillips, M. M., Li, Weidong, Frieman, Joshua A., Blinnikov, S. I., DePoy, Darren, Prieto, José L., ...
The peculiar SN 2005hk: Do some type ia supernovae explode as deflagrations? (2007)
Phillips, M. M., Li, Weidong, Frieman, Joshua A., Blinnikov, S. I., DePoy, Darren, Prietro, Jose L., ...
Publicación ISI
The peculiar SN 2005hk: Do some type ia supernovae explode as deflagrations? (2007)
Phillips, M. M., Li, Weidong, Frieman, Joshua A., Blinnikov, S. I., DePoy, Darren, Prietro, Jose L., ...
Publicación ISI
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...
Smith, Nathan, Li, Weidong, Foley, Ryan J., Wheeler, J. Craig, Pooley, Dave, Chornock, Ryan, ...
(abridged) We report our discovery and observations of the peculiar Type IIn supernova SN2006gy in NGC1260, revealing that it reached a peak magnitude of -22, making it the most luminous supernova...
Deviations From Axisymmetry Revealed by Line Polarization in the Normal Type Ia SN 2004S (2006)
Chornock, Ryan, Filippenko, Alexei V.
We present a single epoch of high signal-to-noise ratio spectropolarimetry of the Type Ia supernova (SN Ia) 2004S taken nine days after maximum light. The flux spectrum is normal, but with the...
XTE J1118+480: A Metal-Rich Black Hole Binary in the Galactic Halo (2006)
Hernandez, Jonay I. Gonzalez, Rebolo, Rafael, Israelian, Garik, Harlaftis, Emilios T., Filippenko, Alexei V., Chornock, Ryan
We present medium-resolution optical spectra of the secondary star in the high Galactic latitude black hole X-ray binary XTE J1118+480 and determine the abundance of Mg, Al, Ca, Fe, and Ni in its...
Spectropolarimetry of the Peculiar Type Ia SN 2005hk (2006)
Chornock, Ryan, Filippenko, Alexei V., Branch, David, Foley, Ryan J., Jha, Saurabh, Li, Weidong
We present Keck spectropolarimetry of the unusual type Ia supernova (SN Ia) 2005hk several days before maximum light. An analysis of the high signal-to-noise-ratio total-flux spectrum shows the...
The Type IIn Supernova 2002kg: The Outburst of a Luminous Blue Variable Star in NGC 2403 (2006)
Van Dyk, Schuyler D., Li, Weidong, Filippenko, Alexei V., Humphreys, Roberta M., Chornock, Ryan, Foley, Ryan, ...
We show that Supernova (SN) 2002kg in NGC 2403, initially classified as Type II-narrow (IIn), has photometric and spectroscopic properties unlike those of normal SNe. Its behavior, instead, is more...
Late-Time Spectroscopy of SN 2002cx: The Prototype of a New Subclass of Type Ia Supernovae (2006)
Jha, Saurabh, Branch, David, Chornock, Ryan, Foley, Ryan J., Li, Weidong, Swift, Brandon J., ...
We present Keck optical spectra of SN 2002cx, the most peculiar known Type Ia supernova (SN Ia), taken 227 and 277 days past maximum light. Astonishingly, the spectra are not dominated by the...
Using Line Profiles to Test the Fraternity of Type Ia Supernovae at High and Low Redshifts (2006)
Blondin, Stéphane, Dessart, Luc, Leibundgut, Bruno, Branch, David, Höflich, Peter, Tonry, John L., ...
Using archival data of low-redshift (z < 0.01; Center for Astrophysics and SUSPECT databases) Type Ia supernovae (SNe Ia) and recent observations of high-redshift (0.16 < z < 0.64) SNe Ia, we study...
Using Line Profiles to Test the Fraternity of Type Ia Supernovae at High and Low Redshifts (2006)
Blondin, Stéphane, Dessart, Luc, Leibundgut, Bruno, Branch, David, Höflich, Peter, Tonry, John L., ...
Using archival data of low-redshift (z < 0.01; Center for Astrophysics and SUSPECT databases) Type Ia supernovae (SNe Ia) and recent observations of high-redshift (0.16 < z < 0.64) SNe Ia, we study...
Evidence for Spectropolarimetric Diversity in Type Ia Supernovae (2005)
Leonard, Douglas C., Li, Weidong, Filippenko, Alexei V., Foley, Ryan J., Chornock, Ryan
We present single-epoch, post-maximum spectropolarimetry of four Type Ia supernovae (SNe Ia) that span a range of spectral and photometric properties: SN 2002bf and SN 2004dt exhibit unusually...
Interstellar Polarization and the Position Angle Orientations of Seyfert 1 Galaxies (2005)
Hoffman, Jennifer L., Chornock, Ryan, Leonard, Douglas C., Filippenko, Alexei V.
We comment on recent spectropolarimetric studies that compare the observed polarization position angles (PAs) of Seyfert 1 galaxies near H alpha with the observed orientations of their radio source...
Riess, Adam G., Li, Weidong, Stetson, Peter B., Filippenko, Alexei V., Jha, Saurabh, Kirshner, Robert P., ...
We report observations of two nearby Type Ia supernovae (SNe Ia) for which observations of Cepheid variables in the host galaxies have been obtained with the Hubble Space Telescope: SN 1994ae in NGC...
The binary progenitor of Tycho Brahe's 1572 supernova (2004)
Ruiz-Lapuente, Pilar, Comeron, Fernando, Mendez, Javier, Canal, Ramon, Smartt, Stephen J., Filippenko, Alexei V., ...
The brightness of type Ia supernovae, and their homogeneity as a class, makes them powerful tools in cosmology, yet little is known about the progenitor systems of these explosions. They are thought...
Riess, Adam G., Strolger, Louis-Gregory, Tonry, John, Casertano, Stefano, Ferguson, Henry C., Mobasher, Bahram, ...
We have discovered 16 Type Ia supernovae (SNe Ia) with the Hubble Space Telescope (HST) and have used them to provide the first conclusive evidence for cosmic deceleration that preceded the current...
The binary progenitor of Tycho Brahe's 1572 supernova (2004)
Ruiz-Lapuente, Pilar, Comeron, Fernado, Méndez, Javier, Canal, Ramon, Smartt, Stephen J., Filippenko, Alexei V., ...
23 High Redshift Supernovae from the IfA Deep Survey: Doubling the SN Sample at z>0.7 (2003)
Barris, Brian J., Tonry, John, Blondin, Stephane, Challis, Peter, Chornock, Ryan, Clocchiatti, Alejandro, ...
We present photometric and spectroscopic observations of 23 high redshift supernovae spanning a range of z=0.34-1.03, 9 of which are unambiguously classified as Type Ia. These supernovae were...
Riess, Adam G., Strolger, Louis-Gregory, Tonry, John, Tsvetanov, Zlatan, Casertano, Stefano, Ferguson, Henry C., ...
We present discoveries of SNe Ia at z > 1 and the photometric diagnostic used to discriminate them from other types of SNe detected during the GOODS Hubble Space Telescope Treasury program with the...
Optical Photometry and Spectroscopy of the SN 1998bw-like Type Ic Supernova 2002ap (2003)
Foley, Ryan J., Papenkova, Marina S., Swift, Brandon J., Filippenko, Alexei V., Li, Weidong, Mazzali, Paolo A., ...
We present optical photometric and spectral data of the peculiar Type Ic SN 2002ap. Photometric coverage includes UBVRI bands from 2002 January 30, the day after discovery, through 2002 December 12....
Li, Weidong, Filippenko, Alexei V., Chornock, Ryan, Jha, Saurabh
We present the technical details of the gamma-ray burst (GRB) alert system of the Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory, and the successful observations of the GRB 020813...
GRB 021004: A Possible Shell Nebula around a Wolf-Rayet Star Gamma-Ray Burst Progenitor (2003)
Mirabal, N., Halpern, J. P., Chornock, Ryan, Filippenko, Alexei V., Terndrup, D. M., Armstrong, E., ...
The rapid localization of GRB 021004 by the HETE-2 satellite allowed nearly continuous monitoring of its early optical afterglow decay, as well as high-quality optical spectra that determined a...
The Early Light Curve of the Optical Afterglow of GRB 021211 (2003)
Li, Weidong, Filippenko, Alexei V., Chornock, Ryan, Jha, Saurabh
The Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory observed GRB 021211 starting 105 s after the burst, among the earliest observations of an optical afterglow to date. Our...
SN 2002cx: The Most Peculiar Known Type Ia Supernova (2003)
Li, Weidong, Filippenko, Alexei V., Chornock, Ryan, Berger, Edo, Berlind, Perry, Calkins, Michael L., ...
We present photometric and spectroscopic observations of supernova (SN) 2002cx, which reveal it to be unique among all observed type Ia supernovae (SNe Ia). SN 2002cx exhibits a SN 1991T-like...
Search for the companions of galactic SNe Ia (2003)
Ruiz-Lapuente, Pilar, Comeron, Fernando, Smartt, Stephen, Kurucz, Robert L., Mendez, Javier, Canal, Ramon, ...
Evidence for Extremely High Dust Polarization Efficiency in NGC 3184 (2002)
Leonard, Douglas C., Filippenko, Alexei V., Chornock, Ryan, Li, Weidong
Recent studies have found the Type II-plateau supernova (SN) 1999gi to be highly polarized (p_max = 5.8%, where p_max is the highest degree of polarization measured in the optical bandpass; Leonard &...
Leonard, Douglas C., Filippenko, Alexei V., Li, Weidong, Matheson, Thomas, Kirshner, Robert P., Chornock, Ryan, ...
We present optical spectra and photometry sampling the first six months after discovery of supernova (SN) 1999gi in NGC 3184. SN 1999gi is shown to be a Type II-plateau event with a photometric...
The magnification of SN 1997ff, the farthest known Supernova (2002)
Benitez, Narciso, Riess, Adam G., Nugent, Peter E., Dickinson, Mark, Chornock, Ryan, Filippenko, Alexei V.
With a redshift of z~1.7, SN 1997ff is the most distant type Ia supernova discovered so far. This SN is close to several bright, z=0.6-0.9 galaxies, and we consider the effects of lensing by those...
Leonard, Douglas C., Filippenko, Alexei V., Chornock, Ryan, Foley, Ryan J.
The early-time optical spectrum of the Type Ic supernova (SN) 2002ap was characterized by unusually broad features, leading some authors to designate it a "hypernova." We present optical...
SDSS J124602.54+011318.8: A Highly Variable AGN, Not an Orphan GRB Afterglow (2002)
Gal-Yam, Avishay, Ofek, Eran O., Filippenko, Alexei V., Chornock, Ryan, Li, Weidong
The optically variable source SDSS J124602.54+011318.8 first appears in Sloan Digital Sky Survey (SDSS) data as a bright point source with nonstellar colors. Subsequent SDSS imaging and spectroscopy...
The Distance to SN 1999em in NGC 1637 from the Expanding Photosphere Method (2001)
Leonard, Douglas C., Filippenko, Alexei V., Gates, Elinor L., Li, Weidong, Eastman, Ronald G., Barth, Aaron J., ...
We present 30 optical spectra and 49 photometric epochs sampling the first 517 days after discovery of supernova (SN) 1999em, and derive its distance through the expanding photosphere method (EPM)....
The Unique Type Ia Supernova 2000cx in NGC 524 (2001)
Li, Weidong, Filippenko, Alexei V., Gates, Elinor, Chornock, Ryan, Gal-Yam, Avishay, Ofek, Eran O., ...
We present extensive photometric and spectroscopic observations of the Type Ia supernova (SN Ia) 2000cx in the S0 galaxy NGC 524, which reveal it to be peculiar. Photometrically, SN 2000cx is...
Helium Emission in the Type Ic SN 1999cq (2000)
Matheson, Thomas, Filippenko, Alexei V., Chornock, Ryan, Leonard, Douglas C., Li, Weidong
We present the first unambiguous detection of helium emission lines in spectra of Type Ic supernovae (SNe Ic). The presence of He I lines, with full width at half maximum ~ 2000 km/s, and the...