Search Publications
Excitation Sources of Oscillations in Solar Coronal Loops: A Multi-wavelength Analysis
Conde C., Sandra M.; Jain, Rekha; Jatenco-Pereira, Vera
An investigation into the excitation sources of oscillations detected in a coronal loop structure is carried out using the images obtained with Interface Region Imaging Spectrometer (IRIS) and the Atmospheric Imaging Assembly (AIA) instrument on board the Solar Dynamics Observatory (SDO). A loop structure in the active region AR 11967 on 2014 Janu…
Spatially Resolved Velocity Structures in Jets of DF Tau and UY Aur A
Principe, David A.; Günther, Hans Moritz; Schneider, P. Christian +1 more
Young stars accrete mass and angular momentum from their circumstellar disks. Some of them also drive outflows, which can be distinguished in optical forbidden emission lines. We analyze a sample of binary T Tauri stars observed with long-slit spectroscopy by the Hubble Space Telescope between 1998 and 2000, searching for spatially resolved outflo…
Swift unveils the orbital period of IGR J18214-1318
Cusumano, G.; La Parola, V.; Segreto, A. +2 more
We analysed 13 yr of the Neil Gehrels Swift Observatory survey data collected on the high-mass X-ray binary IGR J18214-1318. Performing the timing analysis, we detected a periodic signal of 5.42 d. From the companion star characteristics, we derived an average orbital separation of $\sim 41 \rm R_{\odot }\simeq 2 R_{\star }$ . The spectral type of…
Measuring the matter density of the Galactic disc using stellar streams
Malhan, Khyati; Widmark, Axel; Sivertsson, Sofia +1 more
We present a novel method for determining the total matter surface density of the Galactic disc by analysing the kinematics of a dynamically cold stellar stream that passes through or close to the Galactic plane. The method relies on the fact that the vertical component of energy for such stream stars is approximately constant, such that their ver…
Unveiling the Hierarchical Structure of Open Star Clusters: The Perseus Double Cluster
Diaferio, Antonaldo; Li, Lu; Shao, Zhengyi +1 more
We introduce a new kinematic method to investigate the structure of open star clusters. We adopt a hierarchical clustering algorithm that uses the celestial coordinates and the proper motions of the stars in the field of view of the cluster to estimate a proxy of the pairwise binding energy of the stars and arrange them in a binary tree. The clust…
Long photometric cycle and disk evolution in the β Lyrae-type binary OGLE-BLG-ECL-157529
Soszyński, I.; Poleski, R.; Iwanek, P. +4 more
Context. The subtype of hot algol semidetached binaries dubbed double periodic variables (DPVs) are characterized by a photometric cycle longer than the orbital one, whose nature has been related to a magnetic dynamo in the donor component controlling the mass transfer rate.
Aims: We aim to understand the morphologic changes observed in the l…
Multiple AGN activity during the BCG assembly of XDCPJ0044.0-2033 at z ∼ 1.6
Fiore, F.; Piconcelli, E.; Tozzi, P. +13 more
Undisturbed galaxy clusters are characterized by a massive and large elliptical galaxy at their centre, i.e. the brightest cluster galaxy (BCG). How these central galaxies form is still debated. According to most models, a typical epoch for their assembly is $z$ ∼ 1-2. We have performed a detailed multiwavelength analysis of the core of XMM-Newton…
Searching for obscured AGN in z ∼ 2 submillimetre galaxies
Guidetti, D.; Bondi, M.; Prandoni, I. +13 more
Aims: Submillimetre-selected galaxies (SMGs) at high redshift (z ∼ 2) are potential host galaxies of active galactic nuclei (AGN). If the local Universe is a good guide, ∼50% of the obscured AGN amongst the SMG population could be missed even in the deepest X-ray surveys. Radio observations are insensitive to obscuration; therefore, very long…
The flux-weighted gravity-luminosity relation of Galactic classical Cepheids
Groenewegen, M. A. T.
The flux-weighted gravity-luminosity relation (FWGLR) is investigated for a sample of 477 classical Cepheids (CCs), including stars that have been classified in the literature as such but are probably not. The luminosities are taken from the literature, based on the fitting of the spectral energy distributions (SEDs) assuming a certain distance an…
Hα Kinematics of the Isolated Interacting Galaxy Pair KPG 486 (NGC 6090)
Rosado, M.; Sánchez-Cruces, M.; Sardaneta, M. M.
In optical images, the barely studied isolated interacting galaxy pair KPG 486 (NGC 6090) displays similar features to the Antennae (NGC 4038/39) galaxy pair. To compare the distribution of ionized hydrogen gas, morphology and kinematic and dynamic behaviour of both galaxy pairs, we present observations in the Hα emission line of NGC 6090 acquired…