Search Publications
Supernovae in Low-Redshift Galaxy Clusters: Observations by the Wise Observatory Optical Transient Search (WOOTS)
Filippenko, Alexei V.; Maoz, Dan; Gal-Yam, Avishay +1 more
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 present the survey design and data analysis procedures, and our object detection and follow-up strategies. We have obtained follow-up spectroscopy for…
Morphologies of Two Massive Old Galaxies at z ~ 2.5
Stockton, Alan; Canalizo, Gabriela; Iye, Masanori +2 more
We present the results of NICMOS imaging of two massive galaxies photometrically selected to have old stellar populations at z ~ 2.5. Both galaxies are dominated by apparent disks of old stars, although one of them also has a small bulge comprising about one-third of the light at rest-frame 4800 Å. The presence of massive disks of old stars at hig…
Cool and Hot Components of a Coronal Bright Point
He, Jiansen; Tian, Hui; Marsch, Eckart +1 more
We performed a systematic study of the Doppler shifts and electron densities measured in an EUV bright point (hereafter BP) observed in more than 10 EUV lines with formation temperatures from log (T/K) = 4.5 to 6.3. Those parts of a BP seen in transition region and coronal lines are defined as its cool and hot components, respectively. We find tha…
Prospects for the Detection of the Deep Solar Meridional Circulation
Birch, A. C.; Braun, D. C.
We perform helioseismic holography to assess the noise in p-mode travel-time shifts which would form the basis of inferences of large-scale flows throughout the solar convection zone. We also derive the expected travel times from a parameterized return (equatorward) flow component of the meridional circulation at the base of the convection zone fr…
HST NICMOS Imaging of z ~ 2, 24 µm-selected Ultraluminous Infrared Galaxies
Helou, George; Colbert, James; Surace, Jason +3 more
We present Hubble Space Telescope NICMOS H-band imaging of 33 ultraluminous infrared galaxies (ULIRGs) at z ~ 2 that were selected from the 24 µm catalog of the Spitzer Extragalactic First Look Survey. The images reveal that at least 17 of the 33 objects are associated with interactions. Up to one-fifth of the sources in our sample could be …
The Globular Cluster Systems around NGC 3311 and NGC 3309
Whitmore, Bradley C.; Rothberg, Barry; Harris, William E. +2 more
We present extensive new photometry in (g', i') of the large globular cluster (GC) system around NGC 3311, the central cD galaxy in the Hydra cluster. Our GMOS data cover a 5.5' field of view and reach a limiting magnitude i' simeq 26.0, about 0.5 mag fainter than the turnover point of the GC luminosity function. We find that NGC 3311 has a huge p…
Probing the Ionization Structure of the Narrow-Line Region in the Seyfert 1 Galaxy NGC 4151
Kraemer, S. B.; Crenshaw, D. M.; Schmitt, H. R.
We present a study of the distribution of [O III] λ5007 and [O II] λ3727 emission in the narrow-line region (NLR) of the Seyfert 1 galaxy NGC 4151. While the NLR of NGC 4151 exhibits an overall structure consistent with the unified model of Seyfert galaxies, narrowband [O III] and [O II] images obtained with the Wide Field and Planetary Camera 2 a…
Constraints on the Emission and Viewing Geometry of the Transient Anomalous X-Ray Pulsar XTE J1810-197
Gotthelf, E. V.; Perna, Rosalba
The temporal decay of the flux components of the transient anomalous X-ray pulsar XTE J1810-197 following its 2002 outburst presents a unique opportunity to probe the emission geometry of a magnetar. Toward this goal, we model the magnitude of the pulsar's modulation in narrow spectral bands over time. Following previous work, we assume that the p…
Discovery of a Young, Energetic 70.5 ms Pulsar Associated with the TeV Gamma-Ray Source HESS J1837-069
Gotthelf, E. V.; Halpern, J. P.
We report the discovery of 70.5 ms pulsations from the X-ray source AX J1838.0-0655 using the Rossi X-Ray Timing Explorer ( RXTE). PSR J1838-0655 is a rotation-powered pulsar with spin-down luminosity Ė = 5.5 × 1036 ergs s-1, characteristic age τc ≡ P/2dot P = 23 kyr, and surface dipole magnetic field strength B
A New Hubble Space Telescope Distance to NGC 1569: Starburst Properties and IC 342 Group Membership
Mack, Jennifer; Aloisi, Alessandra; van der Marel, Roeland P. +8 more
We present deep HST ACS/WFC photometry of the dwarf irregular galaxy NGC 1569, one of the closest and strongest nearby starburst galaxies. These data allow us, for the first time, to unequivocally detect the tip of the red giant branch and thereby determine the distance to NGC 1569. We find that this galaxy is 3.36 +/- 0.20 Mpc away, considerably …