Search Publications
Constraining X-ray reflection in the low-luminosity AGN NGC 3718 using NuSTAR and XMM-Newton
Zezas, A.; Stern, D.; Bauer, F. E. +9 more
One distinctive feature of low-luminosity active galactic nuclei (LLAGNs) is the relatively weak reflection features they may display in the X-ray spectrum, which can result from the disappearance of the torus with decreasing accretion rates. Some material, however, must surround the active nucleus, i.e. the accretion flow itself and, possibly, a …
Globular cluster ejection, infall, and the host dark matter halo of the Pegasus dwarf galaxy
Beasley, Michael A.; Fahrion, Katja; Leaman, Ryan +10 more
Recent photometric observations revealed a massive, extended (MGC ≳ 105 M⊙; Rh ∼ 14 pc) globular cluster (GC) in the central region (D3D ≲ 100 pc) of the low-mass (M* ∼ 5 × 106 M⊙) dwarf irregular galaxy Pegasus. This massive GC offers a unique opportunity to s…
NuSTAR and Parkes observations of the transitional millisecond pulsar binary XSS J12270-4859 in the rotation-powered state
de Martino, D.; Rea, N.; Torres, D. F. +5 more
We report on the first NuSTAR observation of the transitional millisecond pulsar binary XSS J12270-4859 during its current rotation-powered state, complemented with a 2.5 yr-long radio monitoring at Parkes telescope and archival XMM-Newton and Swift X-ray and optical data. The radio pulsar is mainly detected at 1.4 GHz displaying eclipses over ∼ 4…
Testing the accuracy of 3D-HST photometric redshift estimates as reference samples for deep weak lensing studies
Schrabback, T.; Mahler, G.; Hildebrandt, H. +2 more
Accurate weak lensing mass estimates of clusters are needed to calibrate mass proxies for the cosmological exploitation of galaxy cluster surveys. Such measurements require accurate knowledge of the redshift distribution of the weak lensing source galaxies. In this context, we investigate the accuracy of photometric redshifts (photo-zs) computed b…
A holistic and probabilistic approach to the ground-based and spaceborne data of HAT-P-19 system
Southworth, J.; Mancini, L.; Daylan, T. +5 more
We update the main physical and orbital properties of the transiting hot Saturn planet HAT-P-19 b, based on a global modelling of high-precision transit and occultation light curves, taken with ground-based and space telescopes, archive spectra and radial velocity measurements, brightness values from broad-band photometry, and Gaia parallax. We co…
Effects of metallicity on high-mass X-ray binary formation
Kaaret, P.; Brorby, M.; Ponnada, S.
The heating of the intergalactic medium in the early, metal-poor Universe may have been partly due to radiation from high-mass X-ray binaries (HMXBs). Previous investigations on the effect of metallicity have used galaxies of different types. To isolate the effects of metallicity on the production of HMXBs, we study a sample consisting only of 46 …
Physical properties of the CDFS X-ray sources through fitting spectral energy distributions
Gu, Qiusheng; Guo, Xiaotong; Ding, Nan +2 more
The physical parameters of galaxies and/or active galactic nucleus (AGNs) can be derived by fitting their multiband spectral energy distributions (SEDs). By using CIGALE code, we perform multiband SED fitting (from ultraviolet to infrared) for 791 X-ray sources (518 AGNs and 273 normal galaxies) in the 7 Ms Chandra Deep Field-south survey (CDFS). …
ALMA observations of CS in NGC 1068: chemistry and excitation
Saintonge, A.; Krips, M.; Kohno, K. +14 more
We present results from Atacama Large Millimeter/submillimeter Array (ALMA) observations of CS from the nearby galaxy NGC 1068 (~14 Mpc). This Seyfert 2 barred galaxy possesses a circumnuclear disc (CND, r ~ 200 pc) and a starburst ring (SB ring, r ~ 1.3 kpc). These high-resolution maps (~0.5 arcsec, ~35 pc) allow us to analyse specific sub-region…
Li abundances for solar twins in the open cluster M67
Carlos, Marília; Meléndez, Jorge; do Nascimento, José-Dias +1 more
We determine lithium (Li) abundances for solar twins in the M67 open cluster to add valuable information about the correlation between Li depletion and stellar age and, then, better understand stellar structure and evolution. We use high resolution and good signal-to-noise ratio spectra to characterize Li depletion in three solar twins from M67, u…
New luminous blue variable candidates in the NGC 247 galaxy
Vinokurov, A.; Solovyeva, Y.; Atapin, K. +6 more
We search for luminous blue variable (LBV) stars in galaxies outside the Local Group. Here we present a study of two bright Hα sources in the NGC 247 galaxy. Object j004703.27-204708.4 (MV = -9.08 ± 0.15 mag) shows the spectral lines typical for well-studied LBV stars: broad and bright emission lines of hydrogen and helium He I with P C…