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…
Direct detection of black holes via electromagnetic radiation
Sobrinho, J. L. G.; Augusto, P.
Many black hole (BH) candidates exist, ranging from supermassive (∼106-1010 M⊙) to stellar masses (∼1-100 M⊙), all of them identified by indirect processes. Although there are no known candidate BHs with substellar masses, these might have been produced in the primordial Universe. BHs emit radiation comp…
On the origin of the featureless soft X-ray excess emission from the Seyfert 1 galaxy ESO 198-G24
Dewangan, Gulab C.; Laha, Sibasish; Kembhavi, Ajit K.
We present medium- and high-resolution X-ray spectral study of a Seyfert 1 galaxy ESO 198-G24 using a long (∼122 ks) XMM-Newton observation performed in 2006 February. The source has a prominent featureless soft X-ray excess below 2 keV. This makes the source well suited to investigate the origin of the soft excess. Two physical models - blurred r…
Constraints on the galaxy `main sequence' at z > 5: the stellar mass of HDF850.1
Serjeant, Stephen; Marchetti, Lucia
We present rest-frame optical and near-infrared detections of one of the highest redshift submm-selected galaxies to date, HDF850.1. We do not detect the previously proposed counterpart HDF850.1K in new deep J- and H-band Hubble Space Telescope Wide Field Camera 3 data, placing a strong limit of H - K > 3.8, concluding that the K-band source is…
The pros and cons of the inversion method approach to derive 3D dust emission properties in the ISM: the Hi-GAL field centred on (l, b) = (30°, 0°)
Alves, M. I. R.; Davies, R. D.; Davis, R. J. +13 more
Herschel far-infrared continuum data obtained as part of the Hi-GAL survey have been used, together with the GLIMPSE 8 µm and MIPSGAL 24 µm data, to attempt the first 3D-decomposition of dust emission associated with atomic, molecular and ionized gas at 15 arcmin angular resolution. Our initial test case is a 2 × 2 square degrees regio…
The story of Seyfert galaxy RE J2248-511: from intriguingly ultrasoft to unremarkably average
Page, M. J.; Done, C.; Wiersema, K. +7 more
RE J2248-511 is one of only 14 non-blazar active galactic nuclei (AGN) detected in the far-ultraviolet (FUV) by the ROSAT Wide Field Camera implying a large ultrasoft X-ray flux. This soft X-ray excess is strongly variable on year time-scales, a common property of narrow-line Seyfert 1s, yet its optical line widths classify this source as a broad-…
Discovery of the spectroscopic binary nature of the classical Cepheids FN Aql and V1344 Aql
Szabados, L.; Cseh, B.; Kovács, J. +8 more
We present the analysis of photometric and spectroscopic data of two classical Cepheids, FN Aquilae and V1344 Aquilae. Based on the joint treatment of the new and earlier radial velocity data, both Galactic Cepheids have been found to be a member in a spectroscopic binary system. To match the phases of the earlier radial velocity data correctly wi…
The contribution of CHONS particles to the diffuse high-Galactic-latitude IR emission
Papoular, R.
This work purports to model the far-infrared grey-body emission in the spectra of high-Galactic-latitude clouds. Several carbonaceous laboratory materials are tested for their fitness as carriers of this modified blackbody emission which, according to data delivered by the Planck satellite, and others before, is best fitted with temperature 17.9 K…
Feasibility of transit photometry of nearby debris discs
Kalas, P.; Kenworthy, M. A.; Zeegers, S. T.
Dust in debris discs is constantly replenished by collisions between larger objects. In this paper, we investigate a method to detect these collisions. We generate models based on recent results on the Fomalhaut debris disc, where we simulate a background star transiting behind the disc, due to the proper motion of Fomalhaut. By simulating the exp…
Age-dating the Tully-Fisher relation at moderate redshift
Ferreras, Ignacio; Silk, Joseph; Ziegler, Bodo +1 more
We analyse the Tully-Fisher relation at moderate redshift from the point of view of the underlying stellar populations, by comparing optical and NIR photometry with a phenomenological model that combines population synthesis with a simple prescription for chemical enrichment. The sample comprises 108 late-type galaxies extracted from the FORS Deep…