Search Publications
Spectroscopy of red giants in the globular cluster Terzan 8: kinematics and evidence for the surrounding Sagittarius stream
Bragaglia, A.; D'Orazi, V.; Carretta, E. +3 more
We present the results of a spectroscopic survey of red giants in the globular cluster Terzan 8 with the aim of studying its kinematics. We derived accurate radial velocities for 82 stars located in the innermost 7 arcmin from the cluster centre identifying 48 bona fide cluster members. The kinematics of the cluster have been compared with a set o…
The H i hole and AGB stellar population of the Sagittarius dwarf irregular galaxy . HST proper-motion decontamination
Gullieuszik, M.; Momany, Y.; Clemens, M. +8 more
Using two HST/ACS data sets that are separated by about two years has allowed us to derive the relative proper motion for the Sagittarius dwarf irregular (SagDIG) and reduce the heavy foreground Galactic contamination. The proper-motion decontaminated SagDIG catalog provides a much clearer view of the young red-supergiant and intermediate-age asym…
The effect of sideband ratio on line intensity for Herschel/HIFI
Braine, Jonathan; Ossenkopf, Volker; Higgins, Ronan +8 more
The Heterodyne Instrument for the Far Infrared (HIFI) on board the Herschel Space Observatory is composed of a set of fourteen double sideband mixers. We discuss the general problem of the sideband ratio (SBR) determination and the impact of an imbalanced sideband ratio on the line calibration in double sideband heterodyne receivers. The HIFI SBR …
INTEGRAL and Swift observations of the hard X-ray transient MAXI J1828-249
Ferrigno, C.; Bozzo, E.; Filippova, E.
In this paper we report on the observations performed with INTEGRAL and Swift of the first outburst detected from the hard X-ray transient MAXI J1828-249. During the first about two days of the outburst, the source was observed by MAXI to undergo a very rapid transition from a hard to a softer spectral state. While the hard state was not efficient…
X-ray and UV observations of V751 Cygni in an optical high state
Watson, M. G.; Osborne, J. P.; Page, K. L. +3 more
Aims: The VY Scl system (anti-dwarf nova) V751 Cyg is examined following a claim of a super-soft spectrum in the optical low state.
Methods: A serendipitous XMM-Newton X-ray observation and, 21 months later, Swift X-ray and UV observations, have provided the best such data on this source so far. These optical high-state datasets are used…
Investigation of Cyg OB2 #11(O5 Ifc) by Modelling its Atmosphere
Maryeva, Olga; Zhuchkov, Roman; Malogolovets, Eugene
We continue the study of O-supergiants belonging to the association Cyg OB2 using moderate-resolution spectra. In this paper we present results of the modelling of the stellar atmosphere of Cyg OB2 #11. This object belongs to the spectral class Ofc, which was recently introduced and is yet small in numbers. Ofc class consists of stars with normal …
The XMM-Newton view of the yellow hypergiant IRC + 10420 and its surroundings
Gosset, E.; De Becker, M.; Hutsemékers, D.
Among evolved massive stars likely in transition to the Wolf-Rayet phase, IRC + 10420 is probably one of the most enigmatic. It belongs to the category of yellow hypergiants and it is characterized by quite high mass loss episodes. Even though IRC + 10420 benefited of many observations in several wavelength domains, it has never been a target for …
Azimuthal temperature modulations of Saturn's A ring caused by self-gravity wakes
Spilker, Linda; Morishima, Ryuji; Turner, Neal
The physical temperatures of the Saturn's A ring measured by the Cassini Composite Infrared Spectrometer (CIRS) show quadrupole azimuthal modulations besides temperature drops in Saturn's shadow. These azimuthal modulations are likely to be caused by self-gravity wakes. In this paper, we develop a new thermal model in which wakes are modeled as el…
Enhancement of the Spitzer Infrared Array Camera (IRAC) distortion correction for parallax measurements
Capak, Peter; Kirkpatrick, J. Davy; Lowrance, Patrick J. +6 more
The Spitzer Space Telescope Infrared Array (IRAC) offers a rare opportunity to measure distances and determine physical properties of the faintest and coldest brown dwarfs. The current distortion correction is a 3rd order polynomial represented by TAN-SIP parameters within the headers. The current correction, good to 100 mas, was derive…
Constraint on the gas-to-dust ratio in massive star-forming galaxies at z ∼ 1.4
Iono, Daisuke; Hatsukade, Bunyo; Ohta, Kouji +3 more
We carried out 12CO (J = 2-1) observations toward three star-forming galaxies on the main sequence at z ∼ 1.4 with the Nobeyama 45 m radio telescope. These galaxies have been detected with Spitzer/MIPS in 24 µm, Herschel/SPIRE in 250 µm and 350 µm; their gas metallicity, derived from optical emission line ratios based …