Search Publications
The UDF05 Follow-Up of the Hubble Ultra Deep Field. II. Constraints on Reionization from Z-Dropout Galaxies
Panagia, N.; Gardner, Jonathan P.; Ferguson, H. C. +12 more
We detect three (plus one less certain) z 850-dropout sources in two separate fields (Hubble Ultra Deep Field and NICP34) of our UDF05 Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer images. These z ~ 7 Lyman-break Galaxy (LBG) candidates allow us to constrain the Luminosity Function (LF) of the star-forming ga…
Anomalous magnetosheath flows and distorted subsolar magnetopause for radial interplanetary magnetic fields
Glassmeier, K. H.; Plaschke, F.; McFadden, J. P. +5 more
On 12 August 2007 from 1436 to 1441 UT, when the five THEMIS probes (THA, THB, THC, THD, and THE) were located near the subsolar magnetopause, a sunward flow was observed in the magnetosheath. A fast anti-sunward flow (-280 km/s) was observed in the magnetosheath before the sunward flow. Although THA observed this fast anti-sunward flow, THC and T…
A failed outburst of H1743-322
Belloni, T.; Capitanio, F.; Ubertini, P. +1 more
We report on a campaign of X-ray and soft γ-ray observations of the black hole candidate (BHC) H1743-322 (also named IGR J17464-3213), performed with the RXTE, INTEGRAL and Swift satellites. The source was observed during a short outburst between 2008 October 03 and November 16. The evolution of the hardness-intensity diagram throughout the outbur…
A ~4.6 h quasi-periodic oscillation in the BL Lacertae PKS 2155-304?
Gupta, A. C.; Lachowicz, P.; Gaur, H. +1 more
We report a possible detection of an ~4.6-h quasi-periodic oscillation (QPO) in the 0.3-10 keV emission of the high-energy peaked blazar PKS 2155-304 from a 64 ks observation by the XMM-Newton EPIC/pn detector. We identify a total modulation of ~5% in the light curve and confirm that nominal period by periodogram, structure function, and wavelet a…
The Evolution Of Massive Young Stellar Objects in the Large Magellanic Cloud. I. Identification and Spectral Classification
Brandner, Wolfgang; Chu, You-Hua; Gruendl, Robert A. +5 more
We present and categorize Spitzer infrared spectrometer spectra of 294 objects in the Large Magellanic Cloud (LMC) to create the largest and most complete catalog of massive young stellar object (YSO) spectra in the LMC. Target sources were identified from infrared photometry and multiwavelength images indicative of young, massive stars highly ens…
The Low-Mass Initial Mass Function in the 30 Doradus Starburst Cluster
Moneti, A.; Brandner, W.; Zinnecker, H. +5 more
We present deep Hubble Space Telescope NICMOS 2 F160W band observations of the central 56'' × 57'' (14 pc × 14.25 pc) region around R136 in the starburst cluster 30 Dor (NGC 2070) located in the Large Magellanic Cloud. Our aim is to derive the stellar initial mass function (IMF) down to ~1 M sun in order to test whether the IMF in a mas…
The OGLE view of microlensing towards the Magellanic Clouds - I. A trickle of events in the OGLE-II LMC data
Soszyński, I.; Udalski, A.; Szymański, M. K. +9 more
We present the results from the Optical Gravitational Lensing Experiment II (OGLE-II) survey (1996-2000) towards the Large Magellanic Cloud (LMC), which has the aim of detecting the microlensing phenomena caused by dark matter compact objects in the Galactic halo [massive compact halo objects (MACHOs)].
We use high-resolution Hubble Space Tel…Confirmation of and Variable Energy Injection by a Near-Relativistic Outflow in APM 08279+5255
Brandt, W. N.; Garmire, G. P.; Chartas, G. +2 more
We present results from multi-epoch spectral analysis of XMM-Newton and Chandra observations of the broad absorption line (BAL) quasar APM 08279+5255. Our analysis shows significant X-ray BALs in all epochs with rest-frame energies lying in the range of ~6.7-18 keV. The X-ray BALs and 0.2-10 keV continuum show significant variability on timescales…
RE J1034+396: the origin of the soft X-ray excess and quasi-periodic oscillation
Done, Chris; Ward, Martin; Gierliński, Marek +2 more
The X-ray quasi-periodic oscillation (QPO) seen in RE J1034+396 is so far unique amongst active galactic nuclei (AGN). Here, we look at another unique feature of RE J1034+396, namely its huge soft X-ray excess, to see if this is related in any way to the detection of the QPO. We show that all potential models considered for the soft energy excess …
Time Variability of the Neutral Iron Lines from the Sagittarius B2 Region and Its Implication of a Past Outburst of Sagittarius A
Koyama, Katsuji; Matsumoto, Hironori; Tsuru, Takeshi Go +1 more
We investigated long-term X-ray behavior from the Sgr B2 complex using archival data of the X-ray satellites Suzaku, XMM-Newton, Chandra, and ASCA. The observed region of the Sgr B2 complex included two prominent spots in the FeI Kα line at 6.40keV, a giant molecular cloud, M0.66-0.02, known as the ``Sgr B2 cloud'' and an unusual X-ray source, G0.…