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The faint and extremely red K-band-selected galaxy population in the DEEP2/Palomar fields
Conselice, C. J.; Bundy, K.; Lotz, J. +3 more
We present in this paper an analysis of the faint and red near-infrared (NIR) selected galaxy population found in NIR imaging from the Palomar Observatory Wide-Field Infrared Survey. This survey covers 1.53 deg2 to 5σ detection limits of Kvega = 20.5-21 and Jvega = 22.5, and overlaps with the DEEP2 spectroscopic re…
The Accuracy of Morphological Decomposition of Active Galactic Nucleus Host Galaxies
Urry, C. M.; Simmons, B. D.
In order to assess the accuracy with which we can determine the morphologies of AGN host galaxies, we have simulated more than 50,000 ACS images of galaxies with z < 1.25, using image and noise properties appropriate for the GOODS survey. We test the effect of central point-source brightness on host galaxy parameter recovery with a set of simul…
Frequent Occurrence of High-Speed Local Mass Downflows on the Solar Surface
Kubo, M.; Lites, B. W.; Ichimoto, K. +7 more
We report on new spectropolarimetric measurements with simultaneous filter imaging observation, revealing the frequent appearance of polarization signals indicating high-speed, probably supersonic, downflows that are associated with at least three different configurations of magnetic fields in the solar photosphere. The observations were carried o…
Astrometric and photometric monitoring of GQ Lupi and its sub-stellar companion
Neuhäuser, R.; Schmidt, T. O. B.; Mugrauer, M. +2 more
Context: Neuhäuser et al. (2005, A&A, 435, L13) presented direct imaging evidence for a sub-stellar companion to the young T Tauri star GQ Lupi. Common proper motion was highly significant, but no orbital motion was detected. Faint luminosity, low gravity, and a late-M/early-L spectral type indicated that the companion is either a planet or a …
Chandra Observation of PSR B1823-13 and Its Pulsar Wind Nebula
Pavlov, G. G.; Kargaltsev, O.; Brisken, W. F.
An observation of the Vela-like pulsar B1823-13 and its synchrotron nebula with the Chandra X-Ray Observatory allowed us to resolve the pulsar and the fine structure of the nebula. The pulsar's spectrum fits a power-law model with a photon index ΓPSR ≈ 2.4 for the plausible hydrogen column density nH = 1 × 1022 cm<…
Dust processing in photodissociation regions. Mid-IR emission modelling
Abergel, A.; Habart, E.; Compiègne, M. +1 more
Context: Mid-infrared spectroscopy of dense illuminated ridges (or photodissociation regions, PDRs) suggests dust evolution. Such evolution must be reflected in the gas physical properties through processes like photo-electric heating or H2 formation.
Aims: With Spitzer Infrared Spectrograph (IRS) and ISOCAM data, we study the mid-IR emission …
X-ray variability of the Seyfert 1 Markarian 335: power spectrum and time lags
Arévalo, P.; McHardy, I. M.; Summons, D. P.
To investigate further the comparison between active galactic nuclei (AGN) and black hole X-ray binaries, we have studied the main X-ray variability properties of the Seyfert 1 galaxy Mrk 335. We put particular emphasis on the X-ray time lags, which is a potentially important diagnostic of physical models. From a 100 ks observation by XMM-Newton, …
Direct Detection of the Close Companion of Polaris with the Hubble Space Telescope
Schaefer, Gail H.; Bond, Howard E.; Evans, Nancy Remage +5 more
Polaris, the nearest and brightest classical Cepheid, is a single-lined spectroscopic binary with an orbital period of 30 yr. Using the High Resolution Channel of the Advanced Camera for Surveys on board the Hubble Space Telescope (HST) at a wavelength of ~2255 Å, we have directly detected the faint companion at a separation of 0farcs17. A second …
Gemini Imaging of Mid-Infrared Emission from the Nuclear Region of Centaurus A
Levenson, N. A.; Perlman, Eric; De Buizer, James M. +7 more
We present high spatial resolution mid-IR images of the nuclear region of NGC 5128 (Centaurus A). Images were obtained at 8.8 µm, N band (10.4 µm), and 18.3 µm using the mid-IR imager/spectrometer T-ReCS on Gemini South. These images show a bright unresolved core surrounded by low-level extended emission. We place an upper limit …
On the nature of unabsorbed Seyfert 2 galaxies
Nandra, Kirpal; Brightman, Murray
We present an analysis of six 12µm selected Seyfert 2 galaxies that have been reported to be unabsorbed in the X-ray. By comparing the luminosities of these galaxies in the mid-infrared (12µm), optical ([OIII]) and hard X-ray (2-10keV), we show that they are all underluminous in the 2-10keV X-ray band. Four of the objects exhibit X-ray…