Search Publications
Missions
Journals
Publication Years
3D Spectroscopy with GTC-MEGARA of the Triple AGN Candidate in SDSS J102700.40+174900.8
Shen, Yue; Liu, Xin; Rodríguez-Espinosa, José Miguel +4 more
Triple-active galactic nucleus (AGN) systems are expected to be the result of the hierarchical model of galaxy formation. Since there are very few of them confirmed as such, we present the results of a new study of the triple AGN candidate SDSS J102700.40+174900.8 (center nucleus) through observations with the GTC-MEGARA Integral Field Unit. 1D an…
Discovery of the lensed quasar eRASS1 J050129.5−073309 with SRG/eROSITA and Gaia
Schramm, Malte; Schwope, Axel; Bulbul, Esra +9 more
We report the discovery and spectroscopic identification of the bright doubly lensed quasar eRASS1 J050129.5−073309 at redshift z = 2.47, selected from the first all-sky survey of the Spectrum Roentgen Gamma (SRG) eROSITA telescope and the Gaia EDR3 catalog. We systematically searched for extragalactic sources with eROSITA X-ray positions that hav…
How much large dust could be present in hot exozodiacal dust systems?
Krivov, A. V.; Ertel, S.; Wolf, S. +3 more
Context. An infrared excess over the stellar photospheric emission of main-sequence stars has been found in interferometric surveys, commonly attributed to the presence of hot exozodiacal dust (HEZD). While submicrometer-sized grains in close vicinity to their host star have been inferred to be responsible for the found near-infrared excesses, the…
The Missing Link: Testing Galactic Chemical Evolution Models with the First Multi-isotopic Abundances in Solar Twin Stars
Crossfield, Ian J. M.; Freedman, Richard; Lothringer, Joshua +3 more
We present the first isotopic abundances of both 13CO and C18O in solar twin stars and test the results against several galactic chemical evolution (GCE) models with different nucleosynthesis prescriptions. First, we compare M-band spectra from IRTF/iSHELL to synthetic spectra generated from custom solar atmosphere models usi…
Comparative Solar Minima Using the McIntosh Archive
Gibson, Sarah E.; Webb, David F.; Hewins, Ian M. +3 more
The McIntosh Archive consists of four solar cycles (SC20-23) of synoptic maps of solar features (magnetic polarities, coronal holes, filaments, sunspots, plage) that were produced by Patrick McIntosh and his cartographers. In this paper we present the full Archive for the first time and find a hemispheric pattern of coronal hole polarity reflectin…
White dwarf mass-radius relation in theories beyond general relativity
Alam, Khursid; Islam, Tousif
We explore the internal structures of the white dwarfs in two different modified theories of gravity: (i) scalar-tensor-vector gravity and (ii) beyond Horndeski theories of G 3 type. The modification of the gravitational force inside the white dwarf results in the modification of the mass and radius of the white dwarf. We use observatio…
Possible Detection of a Flare-associated Coronal Mass Ejection on an M-dwarf
Wang, J.
We here report a probable detection of a stellar coronal mass ejection (CME) in active M dwarf KIC 8093473 by performing an analysis on its time resolved X-ray spectra observed by the XMM-Newton satellite. Compared to the value at the quiescent state and the interstellar one, our spectral modeling returns a marginal (and probably evolving) excess …
Carte du Ciel and Gaia. I. Astrometry
Prusti, T.; Ness, J. -U.; Muinonen, K. +7 more
Context. The Carte du Ciel archive at the University of Helsinki enables us to see the sky as it was about 120 yr ago. The archive consists of single-exposure and triple-exposure plates between epochs 1896.8-1925.8.
Aims: Our main aim is to find binary and multiple stars by combining Carte du Ciel and Gaia data.
Methods: The plates were …
From binary to singular: The AGN PSO J334.2028+1.4075 under the high-resolution scope
Gurvits, L. I.; Ros, E.; An, T. +6 more
Context. PSO J334.2028+1.4075 (PSO J334) is a luminous quasar located at redshift z = 2.06. The source gained attention when periodic flux density variations were discovered in its optical light curve. These variations were initially interpreted as the variability due to the orbital motion of a supermassive black hole binary (SMBHB) residing in a …
The [S II] Spectral Images of the Planetary Nebula NGC 7009. II. Major Axis
Otsuka, Masaaki; Hyung, Siek; Lee, Seong-Jae
We derived position-velocity density distribution diagrams along the major (PA = 77°) axis of the elliptical planetary nebula NGC 7009 with the Keck HIRES [S II] 6716/6731 Å doublet spectral images. The average densities of the main shell and knots of NGC 7009 derived from the [S II] 6716/6731 Å fluxes integrated over the line of sight indicate a …