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The Host Galaxy of the Quasar HE 0450-2958
Ho, Luis C.; Im, Myungshin; Kim, Minjin +1 more
A recent study suggests that the quasar HE 0450-2958 is hosted by a galaxy substantially fainter than that inferred from the correlation between black hole mass and bulge luminosity. As this result has significant bearings on galaxy and black hole evolution, we revisit the issue by performing an independent analysis of the data, using a two-dimens…
The Toomre Sequence Revisited with HST NICMOS: Nuclear Brightness Profiles and Colors of Interacting and Merging Galaxies
Böker, Torsten; van der Marel, Roeland P.; Zabludoff, Ann I. +4 more
We discuss the near-infrared (NIR) properties of the nuclei in the 11 merging galaxies of the Toomre sequence, based on high spatial resolution J, H, and K imaging data using NICMOS on board the Hubble Space Telescope (HST). The observations are less affected by dust extinction than our previous HST WFPC2 observations and offer higher spatial reso…
Using VO tools to investigate distant radio starbursts hosting obscured AGN in the HDF(N) region
Muxlow, T. W. B.; Beswick, R.; Walton, N. A. +16 more
Context: A 10-arcmin region around the Hubble Deep Field (North) contains 92 radio sources brighter than 40 µJy which are well-resolved by MERLIN+VLA at 0.2arcsec-2' resolution (average size ~1"). 55 of these have Chandra X-ray counterparts in the 2-Ms CDF(N) field including at least 17 with a hard X-ray photon index and high luminosity char…
The First Detection of Compton Reflection in the Low-Mass X-Ray Binary 4U 1705-44 with INTEGRAL and BeppoSax
Zdziarski, Andrzej A.; Ubertini, Pietro; Bazzano, Angela +1 more
We present data from INTEGRAL and BeppoSAX satellites showing spectral state transitions of the neutron star, atoll-type, low-mass X-ray binary 4U 1705-44. Its energy spectrum can be described as the sum of one or two blackbody components, a 6.4 keV Fe line, and a component due to thermal Comptonization. In addition, and for the first time in this…
The Long-Period, Massive Binaries HD 37366 and HD 54662: Potential Targets for Long-Baseline Optical Interferometry
Bolton, C. T.; Fullerton, A. W.; Gies, D. R. +8 more
We present the results from an optical spectroscopic analysis of the massive stars HD 37366 and HD 54662. We find that HD 37366 is a double-lined spectroscopic binary with a period of 31.8187+/-0.0004 days, and HD 54662 is also a double-lined binary with a much longer period of 557.8+/-0.3 days. The primary of HD 37366 is classified as O9.5 V, and…
IGR J17254-3257, a new bursting neutron star
Walter, R.; Lund, N.; Kuulkers, E. +6 more
Aims:The study of the observational properties of uncommonly long bursts from low luminosity sources is important when investigating the transition from a hydrogen - rich bursting regime to a pure helium regime and from helium burning to carbon burning as predicted by current burst theories. On a few occasions X-ray bursts have been observed with …
Saturn's auroral/polar H +3 infrared emission . II. A comparison with plasma flow models
Melin, Henrik; Miller, Steve; Stallard, Tom +5 more
We present a detailed analysis of the H +3 intensity and velocity profiles crossing Saturn's auroral/polar region, as described by Stallard et al. [Stallard, T., Miller, S., Melin, H., Lystrup, M., Dougherty, M., Achilleos, N., 2007. Icarus 189, 1-13], with a view to understanding the magnetospheric processes with which they …
η Muscae: a young detached binary with two identical components
Demircan, O.; Bakış, V.; Eker, Z. +1 more
High-resolution (λ/dλ ~ 41000) echelle spectra of the multiple system η Muscae were analysed. Precise spectroscopic orbital elements of the close pair η Muscae-A were obtained by means of two techniques; cross-correlation and spectral disentangling. The updated light elements of the close pair were derived using new photometric and spectroscopic d…
NICMOS Observations of Shocked H2 in Orion
Schultz, A. S. B.; Colgan, Sean W. J.; Hollenbach, D. J. +2 more
HST NICMOS narrowband images of the shocked molecular hydrogen emission in OMC-1 are analyzed to reveal new information on the BN/KL outflow. The outstanding morphological feature of this region is the array of molecular hydrogen ``fingers'' emanating from the general vicinity of IRc2 and the presence of several Herbig-Haro objects. The NICMOS ima…
The Opacity of Spiral Galaxy Disks. VIII. Structure of the Cold ISM
Calzetti, D.; Gordon, K. D.; Allen, Ronald J. +6 more
The quantity of dust in a spiral disk can be estimated using the dust's typical emission or the extinction of a known source. In this paper we compare two techniques, one based on emission and one on absorption, applied to sections of 14 disk galaxies. The two measurements reflect, respectively, the average and apparent optical depth of a disk sec…