Search Publications
On ancient solar-type stars
Fuhrmann, Klaus; Chini, Rolf
We describe a survey of ancient solar-type stars down to main-sequence effective temperatures Teff ≥ 5300 K and within 42 pc of the Sun. The underlying Gaia-based, volume-complete parent sample consists of 1633 sources, dominated by Population I. The design of the survey is such that around 130 sources are expected to be members of Popu…
Optical counterparts of an ultraluminous X-Ray Source X-1 in NGC 2500
Akyuz, A.; Aksaker, N.; Avdan, S. +1 more
We present the results of a search for optical counterparts of ultraluminous X-ray source (ULX) X-1 in the nearby galaxy NGC 2500 by using archival images taken with the Hubble Space Telescope Wide Field Camera (WFC3)/UVIS. We identified four optical sources as possible counterparts within the 2σ error radius of 0^' ' }.3 in the images.…
A Magellanic origin for the Virgo sub-structure
Belokurov, V.; Iorio, G.; Erkal, D. +1 more
The Milky Way halo has been mapped out in recent work using a sample of RR Lyrae stars drawn from a cross-match of Gaia with 2MASS. We investigate the significant residual in this map which we constrain to lie at Galactocentric radii 12 < R < 27 kpc and extend over 2600 deg2 of the sky. A counterpart of this structure exists in bo…
The young star population of Lynds 1188
Kun, M.; Marton, G.; Szegedi-Elek, E. +2 more
We present new results on the young star population of the Lynds 1188 molecular cloud, which is associated with the Cepheus Bubble, a giant interstellar shell around the association Cep OB 2. In order to reveal the star-forming scenario of the molecular cloud located on the supershell, and to understand the history of star formation in the region,…
The nearby evolved stars survey - I. JCMT/SCUBA-2 submillimetre detection of the detached shell of U Antliae
Ventura, Paolo; Goldman, Steven R.; Boyer, Martha L. +24 more
We present the highest resolution single-dish submillimetre observations of the detached shell source U Antliae to date. The observations were obtained at 450 and 850 {µ}m with SCUBA-2 instrument on the James Clerk Maxwell Telescope as part of the Nearby Evolved Stars Survey. The emission at 850 {µ}m peaks at 40 arcsec with hints of a …
On the origin of the dramatic spectral variability of WPVS 007
Xue, Yongquan; Li, Junyao; Wang, Tinggui +2 more
We report the discovery of large-amplitude mid-infrared variabilities (MIR; ∼0.3 mag) in the Wide-field Infrared Survey Explorer W1 and W2 bands of the low-luminosity narrow-line Seyfert 1 galaxy WPVS 007, which exhibits prominent and varying broad-absorption lines (BALs) with blueshifted velocity up to {∼ } 14 000km s^{-1}. The observed significa…
Physical properties of the fullerene C60-containing planetary nebula SaSt2-3
Otsuka, Masaaki
We perform a detailed analysis of the fullerene C60-containing planetary nebula (PN) SaSt2-3 to investigate the physical properties of the central star (B0-1II) and nebula based on our own Subaru/HDS spectra and multiwavelength archival data. By assessing the stellar absorption, we derive the effective temperature, surface gravity, and …
Probing inhomogeneity in the helium ionizing UV background
Kim, Tae-Sun; Syphers, David; Pieri, Matthew M. +1 more
We present an analysis combining the simultaneous measurement of intergalactic absorption by hydrogen ({{H {I}}}), helium ({{He {II}}}), and oxygen ({{O {VI}}}) in UV and optical quasar spectra. The combination of the {{H {I}}} and {{He {II}}} Lyman-alpha forests through η (the ratio of column densities of singly ionized helium to neutral hydrogen…
Optical observations and CYCLOPS post-shock region modelling of the polar V348 Pav
Belloni, Diogo; Rodrigues, Claudia V.; Diaz, Marcos P. +3 more
Post-shock regions (PSR) of polar cataclysmic variables (CVs) produce most of their luminosity and give rise to high circular polarization in optical wavelengths and strong variability on the white dwarf (WD) rotation period, which are distinctive features of these systems. To investigate the polar candidate V348 Pav, we obtained a comprehensive o…
Unveiling the nature of candidate high-mass young stellar objects in the Magellanic Clouds with near-IR spectroscopy
Meixner, Margaret; Reiter, Megan; Nayak, Omnarayani +1 more
As nearby neighbours to the Milky Way, the Large and Small Magellanic Clouds (LMC and SMC) provide a unique opportunity to study star formation in the context of their galactic ecosystems. Thousands of young stellar objects (YSOs) have been characterized with large-scale Spitzer and Herschel surveys. In this paper, we present new near-IR spectrosc…