A Multiwavelength Spectral and Polarimetric Study of the Jet of 3C 264 (2009)
Perlman, Eric S., Padgett, C. Alex, Georganopoulos, Markos, Worrall, Diana M., Kastner, Joel H., Franz, Geoffrey, ...
We present a comprehensive multiband spectral and polarimetric study of the jet of 3C 264 (NGC 3862). Included in this study are three HST optical and ultraviolet polarimetry data sets, along with...
An optical spectroscopic survey of the 3CR sample of radio galaxies with z (2009)
Buttiglione, Sara, Capetti, Alessandro, Celotti, Annalisa, Axon, David J., Chiaberge, Marco, Macchetto, F. Duccio, ...
We use the emission line measurements of 3CR radio sources with redshift < 0.3, to explore their spectroscopic properties. The 3CR sources show a bimodal distribution of Excitation Index, a new...
HST/ACS Emission Line Imaging of Low Redshift 3CR Radio Galaxies I: The Data (2009)
Tremblay, Grant R., Chiaberge, Marco, Sparks, William B., Baum, Stefi A., Allen, Mark G., Axon, David J., ...
We present 19 nearby (z
Detection of circular polarization in light scattered from photosynthetic microbes (2009)
Sparks, William B., Hough, James, Germer, Thomas A., Chen, Feng, DasSarma, Shiladitya, DasSarma, Priya, ...
The identification of a universal biosignature that could be sensed remotely is critical to the prospects for success in the search for life elsewhere in the universe. A candidate universal...
Low-power Radio Galaxies in the Distant Universe: A search for FRI at 1 (2009)
Chiaberge, Marco, Tremblay, Grant, Capetti, Alessandro, Macchetto, F. Duccio, Tozzi, Paolo, Sparks, William B.
We present a search for FRI radio galaxies between 1 < z < 2 in the COSMOS field. In absence of spectroscopic redshift measurements, the selection method is based on multiple steps which make use of...
An optical spectroscopic survey of the 3CR sample of radio galaxies with z (2009)
Buttiglione, Sara, Capetti, Alessandro, Celotti, Annalisa, Axon, David J., Chiaberge, Marco, Macchetto, F. Duccio, ...
We present a homogeneous and 92 % complete dataset of optical nuclear spectra for the 113 3CR radio sources with redshifts < 0.3, obtained with the Telescopio Nazionale Galileo. For these sources we...
Bond, Howard E., Sparks, William B.
The luminous Galactic Cepheid RS Puppis is unique in being surrounded by a dust nebula illuminated by the variable light of the Cepheid. In a recent paper in this journal, Kervella et al. (2008)...
Christopher P. O'dea, Anton M. Koekemoer, Stefi A. Baum, William B. Sparks, Andre R, Mark G. Allen, ...
We present new HST STIS/MAMA near-UV images and archival WFPC2 V and R band images which reveal the presence of four star forming regions in an arc along the edge of the dust lane in the giant (4...
Sparks, William B., Bond, Howard E., Cracraft, Misty, Levay, Zolt, Crause, Lisa A., Dopita, Michael A., ...
Following the outburst of the unusual variable star V838 Monocerotis in 2002, a spectacular light echo appeared. A light echo provides the possibility of direct geometric distance determination,...
On the nature of optical nuclei in FR I radio-galaxies from ACS/HST imaging polarimetry (2007)
Capetti, Alessandro, Axon, David J., Chiaberge, Marco, Sparks, William B., Macchetto, F. Duccio, Cracraft, Misty, ...
We obtained optical imaging polarimetry with the ACS/HRC aboard the HST of the 9 closest radio-galaxies in the 3C catalogue with an FR I morphology. The nuclear sources seen in direct HST images in...
Infrared Emission from the Nearby Cool Core Cluster Abell 2597 (2007)
Donahue, Megan, Jordan, Andres, Baum, Stefi A., Cote, Patrick, Ferrarese, Laura, Goudfrooij, Paul, ...
We observed the brightest central galaxy (BCG) in the nearby (z=0.0821) cool core galaxy cluster Abell 2597 with the IRAC and MIPS instruments on board the Spitzer Space Telescope. The BCG was...
On the nature of optical nuclei in FR I radio-galaxies from ACS/HST imaging polarimetry (2007)
Capetti, Alessandro, Axon, David J., Chiaberge, Marco, Sparks, William B., Macchetto, F. Duccio, Cracraft, Misty, ...
We obtained optical imaging polarimetry with the ACS/HRC aboard the HST of the 9 closest radio-galaxies in the 3C catalogue with an FR I morphology. The nuclear sources seen in direct HST images in...
Isophotal Structure and Dust Distribution in Radio-Loud Elliptical Galaxies (2007)
Tremblay, Grant R., Chiaberge, Marco, Donzelli, Carlos J., Quillen, Alice C., Capetti, Alessandro, Sparks, William B., ...
We investigate isophotal properties and dust morphology in the nuclear regions of 84 radio galaxies, imaged in the optical and near-infrared as part of Hubble Space Telescope snapshot surveys. We...
The Mid-Infrared Emission of M87 (2007)
Perlman, E. S., Mason, R. E., Packham, Christopher, Levenson, N. A., Elitzur, M., Schaefer, Justin J., ...
We discuss Subaru and Spitzer Space Telescope imaging and spectroscopy of M87 in the mid-infrared from 5-35 um. These observations allow us to investigate mid-IR emission mechanisms in the core of...
Jester, Sebastian, Meisenheimer, Klaus, Martel, André R., Perlman, Eric S., Sparks, William B.
We present far-ultraviolet (far-UV) observations at ~150 nm of the jet of quasar 3C273 obtained with the Advanced Camera for Surveys (ACS) Solar Blind Channel onboard the Hubble Space Telescope....
Discovery of thirteen novae candidates in M87 (2006)
Madrid, Juan P., Sparks, William B., Ferguson, Henry C., Livio, Mario, Macchetto, Duccio
We have made thirteen positive identifications of near-ultraviolet (NUV) transient sources in the giant elliptical galaxy M87 using the Space Telescope Imaging Spectrograph (STIS) on board the Hubble...
Optical Polarimetry of the Jets of Nearby Radio Galaxies: I. The Data (2006)
Perlman, Eric S., Padgett, C. A., Georganopoulos, Markos, Sparks, William B., Biretta, John A., O'Dea, Christopher P., ...
We present an overview of new HST imaging polarimetry of six nearby radio galaxies with optical jets. These observations triple the number of extragalactic jets with subarcsecond-resolution optical...
Madrid, Juan P., Chiaberge, Marco, Floyd, David, Sparks, William B., Macchetto, Duccio, Miley, George K., ...
We present newly acquired images of the near-infrared counterpart of 3CR radio sources. All the sources were selected to have a redshift of less than 0.3 to allow us to obtain the highest spatial...
Optical polarimetry of the jets of nearby radio galaxies. I. The data (2006)
Perlman, Eric S., Padgett, C. A., Georganopoulos, Markos, Sparks, William B., Biretta, John A., O'Dea, Christopher P., ...
We present an overview of new HST imaging polarimetry of six nearby radio galaxies with optical jets. These observations triple the number of extragalactic jets with subarcsecond-resolution optical...
The Jet and Circumnuclear Environment of 3C 293 (2005)
Floyd, David J. E., Perlman, Eric, Leahy, J. Patrick, Beswick, R. J., Jackson, Neal J., Sparks, William B., ...
We present the new HST near-infrared polarimetry, broad and narrow-band imaging, and MERLIN 4.5GHz Multi-Frequency Synthesis radio imaging of 3C 293, a unique radio galaxy whose host is an obvious...
The Warped Nuclear Disk of Radio Galaxy 3C 449 (2005)
Tremblay, Grant R., Quillen, Alice C., Floyd, David J. E., Noel-Storr, Jacob, Baum, Stefi A., Axon, David, ...
Among radio galaxies containing nuclear dust disks, the bipolar jet axis is generally observed to be perpendicular to the disk major axis. The FR I radio source 3C 449 is an outlier to this...
Arribas, Santiago, Gilliland, Ronald L., Sparks, William B., Lopez-Martin, Luis, Mediavilla, Evencio, Gomez-Alvarez, Pedro, ...
We explore the use of Integral Field Spectroscopy (IFS) to observe extrasolar planet transits. Although this technique should find its full potential in space observations (e.g. JWST, TPF), we have...
Two Clusters with Radio-quiet Cooling Cores (2005)
Donahue, Megan, Voit, G. Mark, O'Dea, Christopher P., Baum, Stefi A., Sparks, William B.
Radio lobes inflated by active galactic nuclei at the centers of clusters are a promising candidate for halting condensation in clusters with short central cooling times because they are common in...
Romaniello, Martino, Patat, Ferdinando, Panagia, Nino, Sparks, William B., Gilmozzi, Roberto, Spyromilio, Jason
We have used FORS1 at the ESO VLT to search for light echoes in imaging polarimetry from four historical supernovae in the face-on nearby spiral galaxy M83 (NGC 5236). No echoes were detected around...
The infrared-dominated jet of 3C401 (2005)
Chiaberge, Marco, Sparks, William. B., Macchetto, F. Duccio, Perlman, Eric, Capetti, Alessandro, Balmaverde, Barbara, ...
We present a Hubble Space Telescope image of the FRII radio galaxy 3C 401, obtained at 1.6 microns with the NICMOS camera in which we identify the infrared counterpart of the brightest region of the...
X-ray and Optical Filaments in M87 (2004)
Sparks, William B., Donahue, Megan, Jordan, Andres, Ferrarese, Laura, Cote, Patrick
We compare a very deep X-ray image of M87, at the center of the Virgo Cluster, to high-quality optical images of the low excitation emission-line gas in the same region. There are striking...
Month-Timescale Optical Variability in the M87 Jet (2003)
Perlman, Eric S., Harris, D. E., Biretta, John A., Sparks, William B., Macchetto, F. Duccio
A previously inconspicuous knot in the M87 jet has undergone a dramatic outburst and now exceeds the nucleus in optical and X-ray luminosity. Monitoring of M87 with the Hubble Space Telescope and...
An energetic stellar outburst accompanied by circumstellar light echoes (2003)
Bond, Howard E., Henden, Arne, Levay, Zoltan G., Panagia, Nino, Sparks, William B., Starrfield, Sumner, ...
Some classes of stars, including supernovae and novae, undergo explosive outbursts that eject stellar material into space. In 2002, the previously unknown variable star V838 Monocerotis brightened...
Imaging Spectroscopy for Extrasolar Planet Detection (2002)
Sparks, William B., Ford, Holland C.
Coronagraphic imaging in combination with moderate to high spectral resolution may prove more effective in both detecting extrasolar planets and characterizing them than a standard coronagraphic...
Chiaberge, Marco, Gilli, Roberto, Macchetto, F. Duccio, Sparks, William B., Capetti, Alessandro
The HST/STIS ultraviolet image of the FR I radio galaxy 3C270 shows the presence of a jet-like structure emerging from the position of the nucleus. This feature, which represents the first jet-like...
The nuclei of radio galaxies in the UV: the signature of different emission processes (2002)
Chiaberge, Marco, Macchetto, F. Duccio, Sparks, William B., Capetti, Alessandro, Allen, Mark G., Martel, Andre' R.
We have studied the nuclei of 28 radio galaxies from the 3CR sample in the UV band. Unresolved nuclei (central compact cores, CCC) are observed in 10 of the 13 FR I, and in 5 of the 15 FR II. All...
Ultraviolet HST Snapshot Survey of 3CR Radio Source Counterparts at Low Redshift (2001)
Allen, Mark G., Sparks, William B., Koekemoer, Anton, Martel, Andre R., O'dea, Christopher P., Baum, Stefi A., ...
We present ultraviolet images of 27 3CR radio galaxies with redshifts z
Filaments and Ionized Gas in the Vicinity of 3C 244.1 (2001)
Feinstein, Carlos, Macchetto, F. Duccio, Martel, Andre R., Sparks, William B.
We present results of Hubble Space Telescope observations of the radio galaxy 3C 244.1. The broadband F702W (R) and F555W (V) images (WFPC2/PC) show an elliptical galaxy and gaseous filaments and...
3C236: Radio Source, Interrupted? (2001)
O'Dea, Christopher P., Koekemoer, Anton M., Baum, Stefi A., Sparks, William B., Martel, Andre R., Allen, Mark G., ...
We present new HST STIS/MAMA near-UV images and archival WFPC2 V and R band images which reveal the presence of four star forming regions in an arc along the edge of the dust lane in the giant (4...
Face-on Dust Disks in Galaxies with Optical Jets (2000)
Sparks, William B., Baum, Stefi A., Biretta, John, Macchetto, F. Duccio, Martel, Andre' R.
The presence of optical synchrotron jets in radio galaxies is relatively rare. Here, we show that of the nearest five FR-I 3CR radio galaxies showing optical jets, {\it four} show evidence for almost...
The Extended Line Region of 3C 299 (1999)
Feinstein, Carlos, Macchetto, F. Duccio, Martel, Andre R., Sparks, William B., McCarthy, Patrick J.
We present results of HST observations of the radio galaxy 3C 299. The broad-band F702W (R) and F555W (V) images (WFPC2/PC) show an elliptical galaxy, with a comet-like structure extending to the NE...
HST Snapshot Survey of 3CR Quasars: The Data (1999)
Lehnert, Matthew D., Miley, George K., Sparks, William B., Baum, Stefi A., Biretta, John, Golombek, Daniel, ...
We present images taken with the Wide Field Planetary Camera (WFPC-2) on the Hubble Space Telescope of 43 quasars selected from the 3CR radio catalog. The redshift range of the targets is large ---...
Optical and Radio Polarimetry of the M87 Jet at 0.2" Resolution (1999)
Perlman, Eric S., Biretta, John A., Zhou, Fang, Sparks, William B., Macchetto, F. Duccio
We discuss optical (HST/WFPC2 F555W) and radio (15 GHz VLA) polarimetry observations of the M87 jet taken during 1994-1995. Many knot regions are very highly polarized ($\sim 40-50%$, approaching the...
Detection of circular polarization in light scattered from photosynthetic microbes
Sparks, William B., Hough, James, Germer, Thomas A., Chen, Feng, DasSarma, Shiladitya, DasSarma, Priya, ...
The identification of a universal biosignature that could be sensed remotely is critical to the prospects for success in the search for life elsewhere in the universe. A candidate universal...