Search Publications
Discovery of a very young high-mass X-ray binary associated with the supernova remnant MCSNR J0513-6724 in the LMC
Haberl, F.; Soszyński, I.; Udalski, A. +20 more
We report the discovery of a very young high-mass X-ray binary (HMXB) system associated with the supernova remnant (SNR) MCSNR J0513-6724 in the Large Magellanic Cloud (LMC), using XMM-Newton X-ray observations. The HMXB is located at the geometrical centre of extended soft X-ray emission, which we confirm as an SNR. The HMXB spectrum is consisten…
Fractal statistics in young star clusters: structural parameters and dynamical evolution
Hetem, Annibal; Gregorio-Hetem, Jane
We used fractal statistics to quantify the degree of observed substructures in a sample of 50 embedded clusters and more evolved open clusters (< 100 Myr) found in different galactic regions. The observed fractal parameters were compared with N-body simulations from the literature, which reproduce star-forming regions under different initial co…
The evolution of carbon-polluted white dwarfs at low effective temperatures
Blouin, Simon; Dufour, Patrick
Taking advantage of the Gaia Data Release 2, recent studies have revisited the evolution of carbon-polluted white dwarfs (DQs) across a large range of effective temperatures. These analyses have clearly confirmed the existence of two distinct DQ evolutionary sequences: one with normal-mass white dwarfs and one with heavily polluted and generally m…
On the size of the CO-depletion radius in the IRDC G351.77-0.51
Menten, K. M.; Schisano, E.; Leurini, S. +5 more
An estimate of the degree of CO-depletion (fD) provides information on the physical conditions occurring in the innermost and densest regions of molecular clouds. A key parameter in these studies is the size of the depletion radius, i.e. the radius within which the C-bearing species, and in particular CO, are largely frozen on to dust g…
The dynamical matter density in the solar neighbourhood inferred from Gaia DR1
Widmark, Axel; Monari, Giacomo
We determine the total dynamical density in the solar neighbourhood using the Tycho-Gaia Astrometric Solution catalogue. Astrometric measurements of proper motion and parallax of stars inform us of both the stellar number density distribution and the velocity distribution of stars close to the plane. Assuming equilibrium, these distributions are i…
New photometric analysis of five exoplanets: CoRoT-2b, HAT-P-12b, TrES-2b, WASP-12b, and WASP-52b
Erdem, Ahmet; Öztürk, Oǧuz
We report 12, 11, 9, 10, and 8 new transit light curves of CoRoT-2b, HAT-P-12b, TrES-2b, WASP-12b, and WASP-52b, respectively, obtained at Çanakkale Onsekiz Mart University Observatory and TÜBİTAK National Observatory in 2016 and 2017. These transit light curves were analysed using JKTEBOP code. Planetary radii of CoRoT-2b, HAT-P-12b, TrES-2b, WAS…
Signatures of an eruptive phase before the explosion of the peculiar core-collapse SN 2013gc
Reichart, D. E.; Smartt, S. J.; Olivares E., F. +12 more
We present photometric and spectroscopic analysis of the peculiar core-collapse supernova (SN) 2013gc, spanning 7 yr of observations. The light curve shows an early maximum followed by a fast decline and a phase of almost constant luminosity. At +200 d from maximum, a brightening of 1 mag is observed in all bands, followed by a steep linear lumino…
SCUBA-2 observations of candidate starbursting protoclusters selected by Planck and Herschel-SPIRE
Andreani, P.; Valtchanov, I.; Clements, D. L. +21 more
We present SCUBA-2 850 µm observations of 13 candidate starbursting protoclusters selected using Planck and Herschel data. The cumulative number counts of the 850 µm sources in 9 of 13 of these candidate protoclusters show significant overdensities compared to the field, with the probability <10-2 assuming the sources are…
Classifying exoplanet candidates with convolutional neural networks: application to the Next Generation Transit Survey
Wheatley, Peter J.; Eigmüller, Philipp; Casewell, Sarah L. +13 more
Vetting of exoplanet candidates in transit surveys is a manual process, which suffers from a large number of false positives and a lack of consistency. Previous work has shown that convolutional neural networks (CNN) provide an efficient solution to these problems. Here, we apply a CNN to classify planet candidates from the Next Generation Transit…
Spectral analysis of the extremely hot DA white dwarf PG 0948+534
Rauch, T.; Werner, K.; Reindl, N.
There is a striking paucity of hydrogen-rich (DA) white dwarfs (WDs) relative to their hydrogen-deficient (non-DA) counterparts at the very hot end of the WD cooling sequence. The three hottest known DAs (surface gravity log g ≥ 7.0) have effective temperatures around T_{eff} = 140 000 K, followed by only five objects in the range 104 000-120 000 …