Search Publications
Origin of the complex iron line structure and spectral variation in Mrk 766
Ebisawa, Ken; Mizumoto, Misaki; Mochizuki, Yuto
Complex Fe-K emission/absorption line features are commonly observed in the 6-11 keV band from Active Galactic Nuclei (AGN). These features are formed in various physical components surrounding the black holes. The Narrow-Line Seyfert 1 (NLS1) galaxy Mrk 766, in particular, exhibits characteristic blue-shifted Fe-K absorption lines caused by the u…
Constraint on the event rate of general relativistic instability supernovae from the early JWST deep field data
Harikane, Yuichi; Inoue, Akio K.; Moriya, Takashi J.
General relativistic instability supernovae (GRSNe) at 10 ≲ z ≲ 15 are predicted to be observed as red faint point sources, and they can be detected only in the reddest filters in James Webb Space Telescope (JWST)/NIRCam (F444W and F356W). They should be observed as persistent point sources with little flux variations for a couple of decades becau…
Confident detection of doubly ionized thorium in the extreme Ap star CPD-62° 2717
Nidever, David L.; Labadie-Bartz, Jonathan; Hasselquist, Sten +4 more
Despite the Universe containing primordial thorium (Th) of sufficient abundance to appear in stellar spectra, detection of Th has to date been tentative and based on just a few weak and blended lines. Here, we present convincing evidence not only for the first Th detection in a magnetic chemically peculiar Ap star but also for the first detection …
Star clusters in tidal debris
Gallagher, Sarah C.; Gronwall, Caryl; Trancho, Gelys +13 more
We present results of a Hubble Space Telescope (HST) UBVI-band study of star clusters in tidal tails, using new WFC3 and ACS imaging to complement existing WFPC2 data. We survey 12 tidal tails across seven merging systems, deriving ages and masses for 425 star cluster candidates (SCCs). The stacked mass distribution across all systems follows a po…
The miniJPAS survey: stellar atmospheric parameters from 56 optical filters
Yuan, H. -B.; Solano, E.; Mendes de Oliveira, C. +29 more
With a unique set of 54 overlapping narrow-band and two broader filters covering the entire optical range, the incoming Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will provide a great opportunity for stellar physics and near-field cosmology. In this work, we use the miniJPAS data in 56 J-PAS filters and 4 compleme…
Photometric variability of blue straggler stars in M67 with TESS and K2
Bowman, Dominic M.; Jadhav, Vikrant V.; Subramaniam, Annapurni +1 more
Blue straggler stars (BSSs) are formed through mass transfers or mergers in binaries. The recent detections of white dwarf (WD) companions to BSSs in M67 suggested a mass transfer pathway of formation. In search of a close companion to five BSSs in M67 that are known to be spectroscopic binaries, we study the light curves from K2 and TESS data. We…
Made-to-measure modelling of globular clusters
Bovy, Jo; Hunt, Jason A. S.; Webb, Jeremy J.
We present the first application of the made-to-measure method for modelling dynamical systems to globular clusters. Through the made-to-measure algorithm, the masses of individual particles within a model cluster are adjusted while the system evolves forward in time via a gravitational N-body code until the model cluster is able to reproduce sele…
Formation and thermodynamic evolution of plasmoids in active region jets
Del Zanna, Giulio; Mulay, Sargam M.; Tripathi, Durgesh +2 more
We have carried out a comprehensive study of the temperature structure of plasmoids, which successively occurred in recurrent active region jets. The multithermal plasmoids were seen to be travelling along the multithreaded spire as well as at the footpoint region in the EUV/UV images recorded by the Atmospheric Imaging Assembly (AIA). The differe…
Modelling the variable emission states of γ-ray-emitting narrow-line Seyfert 1 galaxies
Luashvili, Anna; Boisson, Catherine; Zech, Andreas +2 more
γ-ray-emitting narrow-line Seyfert 1 galaxies (γ-NLS1) constitute an intriguing small population of active galactic nuclei with γ-ray emission resembling low-power flat-spectrum radio quasars (FSRQ), but with differing physical properties. They are jetted, γ/radio-loud Seyfert galaxies, with relatively low black hole masses, accreting at exception…
Far-infrared polarization of the supernova remnant Cassiopeia A with SOFIA HAWC +
Hoang, Thiem; Kirchschlager, Florian; Tram, Le Ngoc +8 more
We present polarization observations of the young supernova remnant (SNR) Cas A using the High-resolution Airborne Wideband Camera-Plus (HAWC +) instrument onboard the Stratospheric Observatory for Infrared Astronomy (SOFIA). The polarization map at 154 $\mu$m reveals dust grains with strong polarization fractions (5-30 per cent), supporting previ…