Search Publications
Optical counterparts of two ULXs in NGC 5474 and NGC 3627 (M 66)
Akyuz, A.; Aksaker, N.; Avdan, S. +6 more
We identified two optical counterparts of brightest ultraluminous X-ray sources (ULXs) in galaxies NGC 5474 and NGC 3627 (M66). The counterparts in Hubble Space Telescope images are very faint, their V magnitudes are 24.7 (MV ≈ -4.5) and 25.9 (MV ≈ -4.2), respectively. NGC 5474 X-1 changes the X-ray flux more than two orders …
Interpreting the ionization sequence in star-forming galaxy emission-line spectra
Ferland, Gary J.; Hewett, Paul C.; Baldwin, Jack A. +4 more
High-ionization star-forming (SF) galaxies are easily identified with strong emission-line techniques such as the BPT diagram, and form an obvious ionization sequence on such diagrams. We use a locally optimally emitting cloud model to fit emission-line ratios that constrain the excitation mechanism, spectral energy distribution, abundances and ph…
The nuclear and integrated far-infrared emission of nearby Seyfert galaxies
Esquej, P.; Hernán-Caballero, A.; Acosta-Pulido, J. A. +11 more
We present far-infrared (FIR) 70-500 µm imaging observations obtained with Herschel/Photodetector Array Camera (PACS) and Spectral and Photometric Imaging REceiver (SPIRE) of 33 nearby (median distance of 30 Mpc) Seyfert galaxies from the Revised Shapley-Ames (RSA) catalogue. We obtain the FIR nuclear (r = 1 kpc and r = 2 kpc) and integrated…
Evidence for a binary origin of a central compact object
Klochkov, Dmitry; Kavanagh, Patrick; Doroshenko, Victor +3 more
Central compact objects (CCOs) are thought to be young thermally emitting isolated neutron stars that were born during the preceding core-collapse supernova explosion. Here, we present evidence that at least in one case the CCO could have been formed within a binary system. We show that the highly reddened optical source IRAS 17287-3443, located 2…
Measure the distance and extinction for stars in LAMOST survey with Bayesian method
Shi, Jianrong; Zhang, Yong; Wu, Yue +7 more
Using a Bayesian technique, which combines both photometric and spectral information, as well as prior knowledge on the Milky Way, we measured the distance and extinction for about one million stars in the first data release of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) survey. Simulations have been performed based on t…
Push it to the limit: Local Group constraints on high-redshift stellar mass functions for M⋆ ≥ 105 M⊙
Weisz, Daniel R.; Bullock, James S.; Boylan-Kolchin, Michael +1 more
We constrain the evolution of the galaxy stellar mass function from 2 < z < 5 for galaxies with stellar masses as low as 105 M⊙ by combining star formation histories of Milky Way satellite galaxies derived from deep Hubble Space Telescope observations with merger trees from the ELVIS suite of N-body simulations. This ap…
Using XMM-Newton to study the energy-dependent variability of H 1743-322 during its 2014 outburst
Stiele, H.; Yu, W.
Black hole transients evolve during bright outbursts, showing distinct changes in their spectral and variability properties. These changes are interpreted as evidence for changes in the accretion flow and in the X-ray-emitting regions. We obtained an anticipated XMM-Newton Target of Opportunity observation of H 1743-322 during its outburst in 2014…
The Planck-ATCA Co-eval Observations project: analysis of radio source properties between 5 and 217 GHz
De Zotti, Gianfranco; Bonaldi, Anna; Lopez-Caniego, Marcos +3 more
The Planck-ATCA Co-eval Observations (PACO) project has yielded observations of 464 sources with the Australia Telescope Compact Array (ATCA) between 4.5 and 40 GHz. The main purpose of the project was to investigate the spectral properties of mm-selected radio sources at frequencies below and overlapping with the ESA's Planck satellite frequency …
Orbital evolution and search for eccentricity and apsidal motion in the eclipsing HMXB 4U 1700-37
Paul, Biswajit; Islam, Nazma
In the absence of detectable pulsations in the eclipsing high-mass X-ray binary 4U 1700-37, the orbital period decay is necessarily determined from the eclipse timing measurements. We have used the earlier reported mid-eclipse time measurements of 4U 1700-37 together with the new measurements from long-term light curves obtained with the all sky m…
Multiwavelength observations of the blazar 1ES 1011+496 in Spring 2008
Maraschi, L.; Covino, S.; Antonelli, L. A. +157 more
The BL Lac object 1ES 1011+496 was discovered at very high energy (VHE, E > 100GeV) γ-rays by Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) in Spring 2007. Before that the source was little studied in different wavelengths. Therefore, a multiwavelength (MWL) campaign was organized in Spring 2008. Along MAGIC, the MWL campaign included t…