Pian, Elena, Romano, Patrizia, Maoz, Dan, Cucchiara, Antonino, Pagani, Claudio, La Parola, Valentina
We have observed four low-luminosity active galactic nuclei classified as Type 1 LINERs with the X-ray Telescope (XRT) and the UltraViolet-Optical Telescope (UVOT) onboard Swift, in an attempt to...
Broad-line region size and black hole mass in high-z AGN (2008)
Botti, Ismael, Lira, Paulina, Netzer, Hagai, Kaspi, Shai, Maza, Jose, Maoz, Dan
In this contribution we briefly review the reverberation mapping technique and its results for low and intermidiate luminosity AGNs. Then we present a monitoring campaign of high-luminosity...
The Rate of Type Ia Supernovae at z~0.2 from SDSS-I Overlapping Fields (2008)
Horesh, Assaf, Poznanski, Dovi, Ofek, Eran O., Maoz, Dan
In the course of the Sloan Digital Sky Survey (SDSS-I), a large fraction of the surveyed area was observed more than once due to field tiling overlap, usually at different epochs. We utilize some of...
A Search for the Progenitors of Two Type-Ia Supernovae in NGC 1316 (2008)
Recent evidence of a young progenitor population for many Type-Ia SNe (SNe-Ia) raises the possibility that evolved intermediate-mass progenitor stars may be detected in pre-explosion images. NGC...
Gal-Yam, Avishay, Maoz, Dan, Guhathakurta, Puragra, Filippenko, Alexei V.
We describe the Wise Observatory Optical Transient Search (WOOTS), a survey for supernovae (SNe) and other variable and transient objects in the fields of redshift 0.06-0.2 Abell galaxy clusters. We...
Bayesian single-epoch photometric classification of supernovae (2007)
Poznanski, Dovi, Maoz, Dan, Gal-Yam, Avishay
Ongoing supernova (SN) surveys find hundreds of candidates that require confirmation for their various uses. Traditional classification based on follow- up spectroscopy of all candidates is virtually...
Rupke, David, Veilleux, Sylvain, Kim, DongChan, Sturm, Eckhard, Contursi, Alessandra, Lutz, Dieter, ...
The impact of active galactic nuclei on low-ionization nuclear emission-line regions (LINERs) remains a vigorous field of study. We present preliminary results from a study of the mid-infrared atomic...
On the fraction of intermediate-mass close binaries that explode as type-Ia supernovae (2007)
Type-Ia supernovae (SNe-Ia) are thought to result from a thermonuclear runaway in white dwarfs (WDs) that approach the Chandrasekhar limit, either through accretion from a companion or a merger with...
Supernovae in the Subaru Deep Field: An Initial Sample, and Type Ia Rate, out to Redshift 1.6 (2007)
Poznanski, Dovi, Maoz, Dan, Yasuda, Naoki, Foley, Ryan J., Doi, Mamoru, Filippenko, Alexei V., ...
Large samples of high-redshift supernovae (SNe) are potentially powerful probes of cosmic star formation, metal enrichment, and SN physics. We present initial results from a new deep SN survey, based...
Low-Luminosity Active Galactic Nuclei: Are They UV-Faint and Radio Loud? (2007)
Low-luminosity AGNs are perceived to be radio loud and devoid of a ``big blue bump'', indicating a transition from a radiatively efficient, geometrically thin, accretion disc in high-luminosity AGNs,...
Rupke, David, Veilleux, Sylvain, Kim, DongChan, Sturm, Eckhard, Contursi, Alessandra, Lutz, Dieter, ...
Reverberation Mapping of High-Luminosity Quasars: First Results (2006)
Kaspi, Shai, Brandt, W. N., Maoz, Dan, Netzer, Hagai, Schneider, Donald P., Shemmer, Ohad
Reverberation mapping of nearby active galactic nuclei has led to estimates of broad-line-region (BLR) sizes and central-object masses for some 37 objects to date. However, successful reverberation...
Supernovae in Low-Redshift Galaxy Clusters: the Type-Ia Supernova Rate (2006)
Sharon, Keren, Gal-Yam, Avishay, Maoz, Dan, Filippenko, Alexei V., GuhaThakurta, Puragra
Supernova (SN) rates are a potentially powerful diagnostic of star formation history (SFH), metal enrichment, and SN physics, particularly in galaxy clusters with their deep, metal-retaining...
Bayesian Single-Epoch Photometric Classification of Supernovae (2006)
Poznanski, Dovi, Maoz, Dan, Gal-Yam, Avishay
(abridged) Ongoing supernova (SN) surveys find hundreds of candidates, that require confirmation for their use. Traditional classification based on followup spectroscopy of all candidates is...
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...
O'Neill, Paul M., Kaspi, Shai, Laor, Ari, Nandra, Kirpal, Moran, Edward C., Peterson, Bradley M., ...
We report on two Chandra observations, and a simultaneous Hubble Space Telescope ultraviolet observation, of the dwarf Seyfert 1 galaxy NGC 4395. Each Chandra observation had a duration of ~30 ks,...
Spectroscopic redshifts for seven lens galaxies (2006)
Ofek, Eran O., Maoz, Dan, Rix, Hans-Walter, Kochanek, Christopher S., Falco, Emilio E.
The use of gravitationally lensed quasars for cosmological applications and as probes of galaxy structure and evolution requires knowledge about the lens redshift, which is unknown for a large...
Spectroscopic Redshifts for Seven Lens Galaxies (2005)
Ofek, Eran O., Maoz, Dan, Rix, Hans-Walter, Kochanek, Christopher S., Falco, Emilio E.
We report VLT observations of 11 lensed quasars, designed to measure the redshifts of their lens galaxies. We successfully determined the redshifts for seven systems, five of which were previously...
Horesh, Assaf, Ofek, Eran O., Maoz, Dan, Bartelmann, Matthias, Meneghetti, Massimo, Rix, Hans-Walter
We compare the statistical properties of giant gravitationally lensed arcs produced in matched simulated and observed cluster samples. The observed sample consists of 10 X-ray selected clusters at...
Discovery of Multiply Imaged Galaxies behind the Cluster and Lensed Quasar SDSS J1004+4112 (2005)
Sharon, Keren, Ofek, Eran O., Smith, Graham P., Broadhurst, Tom J., Maoz, Dan, Kochanek, Christopher S., ...
We have identified three multiply imaged galaxies in Hubble Space Telescope images of the redshift z=0.68 cluster responsible for the large-separation quadruply lensed quasar, SDSS J1004+4112....
Peterson, Bradley M., Bentz, Misty C., Desroches, Louis-Benoit, Filippenko, Alexei V., Ho, Luis C., Kaspi, Shai, ...
A reverberation-mapping program on NGC 4395, the least-luminous known Seyfert 1 galaxy, undertaken with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, yields a measurement of...
The Remnants of Intergalactic Supernovae (2005)
Maoz, Dan, Waxman, Eli, Loeb, Abraham
Intergalactic type-Ia supernovae (SNe-Ia) have been discovered recently in rich galaxy clusters, likely the descendants of an intergalactic stellar population found in recent years through a variety...
The Relationship Between Luminosity and Broad-Line Region Size in Active Galactic Nuclei (2005)
Kaspi, Shai, Maoz, Dan, Netzer, Hagai, Peterson, Bradley M., Vestergaard, Marianne, Jannuzi, Buell T.
We reinvestigate the relationship between the characteristic broad-line region size (R_blr) and the Balmer emission-line, X-ray, UV, and optical continuum luminosities. Our study makes use of the...
Maoz, Dan, Nagar, Neil M., Falcke, Heino, Wilson, Andrew S.
LINER nuclei, which are present in many nearby galactic bulges, may be the manifestation of low-rate or low-radiative-efficiency accretion onto supermassive central black holes. However, it has been...
Quasar Lensing Statistics and Omega_Lambda: What Went Wrong? (2005)
In the pre-WMAP, pre-Supernova-Ia-Hubble-diagram era, quasar lensing statistics stubbornly indicated low values of Omega_Lambda. In contrast, a number of recent lensing statistics studies either find...
Supernova Rates in Galaxy Clusters (2005)
Measurements of SN rates in different environments and redshifts can shed light on the nature of SN-Ia progenitors, star formation history, and chemical enrichment history. I summarize some recent...
Horesh, Assaf, Ofek, Eran O., Maoz, Dan, Bartelmann, Matthias, Meneghetti, Massimo, Rix, Hans-Walter
We compare the statistical properties of giant gravitationally lensed arcs produced in matched simulated and observed cluster samples. The observed sample consists of 10 X-ray-selected clusters at...
Peterson, Bradley, Ferrarese, Laura, Gilbert, Karoline, Kaspi, Shai, Malkan, Matthew, Maoz, Dan, ...
Also archived in: arXiv:astro-ph/0407299 v1 14 Jul 2004
Photometric Identification of Young Stripped-Core Supernovae (2004)
Gal-Yam, Avishay, Poznanski, Dovi, Maoz, Dan, Filippenko, Alexei V., Foley, Ryan J.
We present a method designed to identify the spectral type of young (less than ~30 days after explosion) and nearby (z < ~0.05) supernovae (SNe) using their broad-band colors. In particular, we show...
Constraints on SN Ia Progenitors and ICM enrichment from field and cluster SN rates (2003)
The iron mass in galaxy clusters is about 6 times larger than could have been produced by core-collapse SNe, assuming the stars in cluster galaxies formed with a standard IMF. Type-Ia SNe have been...
We use the redshift distribution of type-Ia supernovae (SNe) discovered by the Supernova Cosmology Project to constrain the star formation history (SFH) of the Universe and SN Ia progenitor models....
The iron mass in galaxy clusters is about 6 times larger than could have been produced by core-collapse supernovae (SNe), assuming the stars in the cluster formed with a standard initial mass...
Using Multi-Band Photometry to Classify Supernovae (2003)
Poznanski, Dovi, Gal-Yam, Avishay, Maoz, Dan, Filippenko, Alexei V., Leonard, Douglas C., Matheson, Thomas
Large numbers of supernovae (SNe) have been discovered in recent years, and many more will be found in the near future. Once discovered, further study of a SN and its possible use as an astronomical...
Time delay measurement of the lensed quasar HE1104-1805 (2003)
We have measured the time delay between the two images of the gravitationally lensed quasar HE1104-1805 by combining observations made with the Wise Observatory 1m telescope and published...
Ofek, Eran O., Rix, Hans-Walter, Maoz, Dan
The redshifts of lens galaxies in known gravitational lens systems probe the volume distribution of lensing mass. Following earlier work by Kochanek, we re-derive the lens redshift probability...
Maoz, Dan, Astrophysics Conference
Talk Abstract von Kongress: Star and Structure Formation: From First Light to the Milky Way, Astrophysics Conference, August 18-22, 2003, ETH Zurich, Switzerland
Ofek, Eran O., Rix, Hans-Walter, Maoz, Dan
The redshifts of lens galaxies in known gravitational lens systems probe the volume distribution of the lensing mass. Following earlier work by Kochanek, we rederive the lens-redshift probability...
A Population of Intergalactic Supernovae in Galaxy Clusters (2002)
Gal-Yam, Avishay, Maoz, Dan, Guhathakurta, Puragra, Filippenko, Alexei V.
We have discovered seven type Ia cluster supernovae (SNe) in the course of the Wise Observatory Optical Transients Search in the fields of galaxy clusters with redshifts between z=0.06 and z=0.2. Two...
Reverberation Mapping of High-Redshift, High-Luminosity Quasars (2002)
Kaspi, Shai, Netzer, Hagai, Maoz, Dan, Shemmer, Ohad, Brandt, W. N., Schneider, Donald P.
We present preliminary results from a reverberation mapping program to measure the Broad Line Region size in high-redshift, high-luminosity quasars. The observations are carried out at the...
Ofek, Eran O., Rix, Hans-Walter, Maoz, Dan, Prada, Francisco
The statistics of large-separation gravitational lensing are a powerful tool to probe mass distributions on the scale of galaxy clusters. In this paper we refine the analysis of our survey for...
X-ray vs. Optical Variations in the Seyfert 1 Nucleus NGC 3516: A Puzzling Disconnectedness (2002)
Maoz, Dan, Markowitz, Alex, Edelson, Rick, Nandra, Kirpal
We present optical broadband (B and R) observations of the Seyfert 1 nucleus NGC 3516, obtained at Wise Observatory from March 1997 to March 2002, contemporaneously with X-ray 2-10 keV measurements...
Comment on "Measuring the black hole masses of high redshift quasars" (2002)
In a recent paper, McLure & Jarvis (2002, astro-ph/0204473, v.1) reanalyze AGN broad-line reverberation measurements presented in Kaspi et al. (2000). They find the broad-line region size and the AGN...
Not Color Blind: Using Multiband Photometry to Classify Supernovae (2002)
Poznanski, Dovi, Gal-Yam, Avishay, Maoz, Dan, Filippenko, Alexei V., Leonard, Douglas C., Matheson, Thomas
Large numbers of supernovae (SNe) have been discovered in recent years, and many more will be found in the near future. Once discovered, further study of a SN and its possible use as an astronomical...
Ofek, Eran O., Rix, Hans-Walter, Maoz, Dan, Prada, Francisco
The statistics of large-separation gravitational lensing are a powerful tool for probing mass distributions on the scale of galaxy clusters. In this paper we refine the analysis of our survey for...
Gal-Yam, Avishay, Maoz, Dan, Sharon, Keren
We have searched for high-redshift supernova (SN) candidates in multiple deep Hubble Space Telescope (HST) archival images of nine galaxy-cluster fields. We detect six apparent SNe, with I814 between...
Maoz, Dan, Ho, Luis C., Sternberg, Amiel
We present 3000--10000 Ang HST/STIS long-slit spectroscopy of the bright super star cluster A (SSC-A) in the dwarf starburst galaxy NGC 1569. The 0.05" HST angular resolution allows, for the first...
Maoz, Dan, Barth, Aaron J., Ho, Luis C., Sternberg, Amiel, Filippenko, Alexei V.
We present broad-band (U, V, I,and H) and narrow-band(H-alpha+[N II] and Paschen-alpha) images of the circumnuclear starburst rings in two nearby spiral galaxies, NGC 1512 and NGC 5248, obtained with...
'Round the Clock Observations of the Q0957+561 A,B Gravitationally Lensed Quasar (2001)
Colley, Wesley N., Schild, Rudolph E., Abajas, Cristina, Alcalde, David, Aslan, Zeki, Barrena, Rafael, ...
An observing campaign with 10 participating observatories has undertaken to monitor the optical brightness of the Q0957 gravitationally lensed quasar for 10 consecutive nights in January 2000. The...
Supernova rates in Abell galaxy clusters and implications for metallicity (1999)
Supernovae (SNe) play a critical role in the metal enrichment of the intra-cluster medium (ICM) in galaxy clusters. Not only are SNe the main source for metals, but they may also supply the energy to...
Supernova rates in Abell galaxy clusters and implications for metallicity (1999)
Supernovae (SNe) play a critical role in the metal enrichment of the intra-cluster medium (ICM) in galaxy clusters. Not only are SNe the main source for metals, but they may also supply the energy to...
Intensive HST, RXTE and ASCA Monitoring of NGC 3516: Evidence Against Thermal Reprocessing (1999)
Edelson, Rick, Koratkar, Anuradha, Nandra, Kirpal, Goad, Michael, Peterson, Bradley M., Collier, Stefan, ...
During 1998 April 13-16, NGC 3516 was monitored almost continuously with HST for 10.3 hr in the UV and 2.8 d in the optical, and simultaneous RXTE and ASCA monitoring covered the same period. The...
Kaspi, Shai, Smith, Paul S., Netzer, Hagai, Maoz, Dan, Jannuzi, Buell T., Giveon, Uriel
(abridged) We have spectrophotometrically monitored a well-defined sample of 28 Palomar-Green quasars in order to obtain measurements of their BLRs and to investigate the relationships between quasar...
A Possible 100-day X-ray-to-Optical Lag in the Variations of the Seyfert 1 Nucleus NGC 3516 (1999)
Maoz, Dan, Edelson, Rick, Nandra, Kirpal
We present optical broadband (B and R) observations of the Seyfert 1 nucleus NGC 3516, obtained at Wise Observatory from 1997 March to 1998 September, contemporaneously with the X-ray 2-10 keV...
A Tully Fisher Relation for S0 Galaxies (1999)
Neistein, Eyal, Maoz, Dan, Rix, Hans-Walter, Tonry, John L.
We present an I-band Tully-Fisher relation (TFR) for 18 nearby S0 galaxies using kinematics derived from long slit spectroscopy of stellar absorption lines. Our estimates of the circular velocity,...
Long-term optical variability properties of the Palomar-Green quasars (1999)
Giveon, Uriel, Maoz, Dan, Kaspi, Shai, Netzer, Hagai, Smith, Paul S.
We present results from a monitoring program of 42 quasars from the Palomar Green sample. The objects were observed for 7 years at the Wise Observatory, as part of a long term effort to monitor AGN...
The Role of Stars in the Energetics of LINERs (1998)
Imaging studies have shown that about 25% of LINER galaxies display a compact nuclear UV source. I compare the HST ultraviolet spectra now available for seven such ``UV-bright'' LINERs. The spectra...
Peterson, Bradley M., Wanders, Ignaz, Horne, Keith, Collier, Stefan, Alexander, Tal, Kaspi, Shai, ...
We describe a model-independent method of assessing the uncertainties in cross-correlation lags determined from AGN light curves, and use this method to investigate the reality of lags between UV and...
The Ultraviolet Spectra of LINERs: A Comparative Study (1997)
Maoz, Dan, Koratkar, Anuradha, Shields, Joseph C., Ho, Luis C., Filippenko, Alexei V., Sternberg, Amiel
Imaging studies have shown that about 25% of LINER galaxies display a compact nuclear UV source. As part of a program to study the nature of LINERs and their connection to the active galaxy...
Detectability of High Redshift Ellipticals in the Hubble Deep Field (1997)
Relatively few intensively star-forming galaxies at redshifts z>2.5 have been found in the Hubble Deep Field (HDF). This has been interpreted to imply a low space density of elliptical galaxies at...
A survey for large image-separation lensed quasars (1996)
Maoz, Dan, Rix, Hans-Walter, Gal-Yam, Avishay, Gould, Andrew
The statistics of gravitationally lensed quasars with multiple images in the 0.1''-7'' range have been measured in various surveys. Little is known, however, about lensed-quasar statistics at larger...
Evidence for a New Class of Extreme UV Sources (1996)
Maoz, Dan, Ofek, Eran, Shemi, Amotz
Most of the sources detected in the extreme ultraviolet (EUV; 100 Ang to 600 Ang) by the Rosat WFC and EUVE all-sky surveys have been identified with active late-type stars and hot white dwarfs that...
Reverberation Mapping and Broad-Line Region Models (1996)
I review what we have learned about the BLR from reverberation mapping, point to some problems and complications that have emerged, and outline some future directions.
Measurement of the Broad Line Region Size in Two Bright Quasars (1996)
Kaspi, Shai, Smith, Paul S., Maoz, Dan, Netzer, Hagai, Jannuzi, Buell. T.
We present 4 years of spectrophotometric monitoring data for two radio-quiet quasars, PG 0804+762 and PG 0953+414, with typical sampling intervals of several months. Both sources show continuum and...
An Atlas of Hubble Space Telescope Ultraviolet Images of Nearby Galaxies (1996)
Maoz, Dan, Filippenko, Alexei V., Ho, Luis C., Macchetto, F. Duccio, Rix, Hans-Walter, Schneider, Donald P.
We present an atlas of UV ($\sim 2300$ \AA) images, obtained with the Hubble Space Telescope (HST) Faint Object Camera, of the central $22''\times 22''$ of 110 galaxies. The observed galaxies are an...
Hubble Space Telescope Ultraviolet Images of Five Circumnuclear Star-Forming Rings (1996)
Maoz, Dan, Barth, Aaron J., Sternberg, Amiel, Filippenko, Alexei V., Ho, Luis C., Macchetto, F. Duccio, ...
We present UV (2300 Ang) images, obtained with the HST Faint Object Camera, of the central 20'' of five galaxies containing circumnuclear star-forming rings. The five galaxies are from a well-defined...
Ultraviolet Imaging and Spectroscopy of LINERs (1995)
I review the UV properties of LINERs (low-ionization nuclear emission-line regions), based mostly on the recent {\it HST} UV imaging survey of nearby galaxies by Maoz et al. (1995). 25 of the...
Optical Identification of Quasar 0917+7122 in the Direction of an Extreme-Ultraviolet Source (1995)
Maoz, Dan, Ofek, Eran, Shemi, Amotz, Barth, Aaron, Filippenko, Alexei, Brotherton, Michael, ...
We report the optical identification of an $R=18.3$ mag, $z=2.432$ quasar at the position of a 6 cm radio source and a faint \rosat PSPC X-ray source. The quasar lies within the error circles of...
Limits on Dust in Rich Clusters of Galaxies from the Color of Background Quasars (1995)
I measure the V-I color distribution of two samples of radio-selected quasars. Quasars from one sample are projected on the sky within 1 degree of a rich foreground Abell cluster of galaxies, while...
Detection of Compact Ultraviolet Nuclear Emission in LINER Galaxies (1994)
Maoz, Dan, Filippenko, Alexei V., Ho, Luis C., Rix, Hans-Walter, Bahcall, John N., Schneider, Donald P., ...
Low-ionization nuclear emission-line regions (LINERs), which exist in a large fraction of galaxies, may be the least luminous manifestation of quasar activity. The nature of LINERs has, however,...
Echo Mappping of the Broad Line Region of AGNs -- A Critical Appraisal (1994)
The results of recent AGN monitoring campaigns confirm the ``big picture'' of the echo paradigm, but the details of the emission-line light curves cannot be accurately reproduced with only the...
Galaxy Mergers and Gravitational Lens Statistics (1994)
Rix, Hans-Walter, Maoz, Dan, Turner, Edwin L., Fukugita, Masataka
We investigate the impact of hierarchical galaxy merging on the statistics of gravitational lensing of distant sources. Since no definite theoretical predictions for the merging history of luminous...
A Spectroscopic Method to Measure Macho Proper Motions (1994)
A Massive Compact Halo Object (Macho) that lenses a background star will magnify different parts of the rotating stellar disk by varying amounts. The differential magnification will cause a shift in...