Search Publications
Phase-dependent Study of Near-infrared Disk Emission Lines in LB-1
Soria, Roberto; Liu, Jifeng; Wang, Shu +18 more
The mass, origin, and evolutionary stage of the binary system LB-1 have been intensely debated, following the claim that it hosts an ∼70M⊙ black hole, in stark contrast with the expectations for Galactic remnants. We conducted a high-resolution, phase-resolved spectroscopic study of its Paschen lines, using the Calar Alto 3.5 m telescop…
The Gaia-ESO Survey: Carbon Abundance in the Galactic Thin and Thick Disks
Kordopatis, Georges; Calura, Francesco; Bragaglia, Angela +24 more
This paper focuses on carbon, which is one of the most abundant elements in the universe and is of high importance in the field of nucleosynthesis and galactic and stellar evolution. The origin of carbon and the relative importance of massive and low- to intermediate-mass stars in producing it is still a matter of debate. We aim at better understa…
2MASS J15460752-6258042: a mid-M dwarf hosting a prolonged accretion disc
Song, Inseok; Lee, Jinhee; Murphy, Simon
We report the discovery of the oldest (∼55 Myr) mid-M type star known to host ongoing accretion. 2MASS J15460752-6258042 (2M1546, spectral type M5, 59.2 pc) shows spectroscopic signs of accretion such as strong H α, He I, and [O I] emission lines, from which we estimate an accretion rate of ∼10-10 M⊙ yr-1. Consider…
Herschel Gould Belt Survey Observations of Dense Cores in the Cepheus Flare Clouds
Ward-Thompson, Derek; Arzoumanian, Doris; Di Francesco, James +17 more
We present Herschel SPIRE and PACS maps of the Cepheus Flare clouds L1157, L1172, L1228, L1241, and L1251, observed by the Herschel Gould Belt Survey of nearby star-forming molecular clouds. Through modified blackbody fits to the SPIRE and PACS data, we determine typical cloud column densities of (0.5-1.0) × 1021 cm-2 and typ…
The STIX Aspect System (SAS): The Optical Aspect System of the Spectrometer/Telescope for Imaging X-Rays (STIX) on Solar Orbiter
Strassmeier, K. G.; Krucker, S.; Mann, G. +28 more
The Spectrometer/Telescope for Imaging X-rays (STIX) is a remote sensing instrument on Solar Orbiter that observes the hard X-ray bremsstrahlung emission of solar flares. This paper describes the STIX Aspect System (SAS), a subunit that measures the pointing of STIX relative to the Sun with a precision of ±4″, which is required to accur…
Implications for the origin and evolution of Martian Recurring Slope Lineae at Hale crater from CaSSIS observations
Pajola, M.; Cremonese, G.; Thomas, N. +9 more
Recurring Slope Lineae (RSL) are narrow, dark features that typically source from rocky outcrops, incrementally lengthen down Martian steep slopes in warm seasons, fade in cold seasons and recur annually. In this study we report the first observations of RSL at Hale crater, Mars, during late southern summer by the Color and Surface Science Imaging…
The White Dwarf Binary Pathways Survey. V. The Gaia White Dwarf Plus AFGK Binary Sample and the Identification of 23 Close Binaries
Gänsicke, B. T.; Rebassa-Mansergas, A.; Raddi, R. +22 more
Close white dwarf binaries consisting of a white dwarf and an A-, F-, G-, or K-type main-sequence star, henceforth close WD+AFGK binaries, are ideal systems to understand the nature of type Ia supernovae progenitors and to test binary evolution models. In this work we identify 775 WD+AFGK candidates from TGAS (The Tycho-Gaia Astrometric Solution) …
The Vanishing and Appearing Sources during a Century of Observations Project. I. USNO Objects Missing in Modern Sky Surveys and Follow-up Observations of a “Missing Star”
Gupta, Alok C.; Kochukhov, Oleg; Krisciunas, Kevin +19 more
In this paper we report the current status of a new research program. The primary goal of the “Vanishing and Appearing Sources during a Century of Observations” project is to search for vanishing and appearing sources using existing survey data to find examples of exceptional astrophysical transients. The implications of finding such objects exten…
Discovery of a Remarkably Powerful Broad Absorption-line Quasar Outflow in SDSS J135246.37+423923.5
Gallagher, Sarah C.; Terndrup, Donald M.; Leighly, Karen M. +2 more
Broad absorption-line (BAL) features in quasar spectra reveal an unambiguous signature of energetic outflows from central supermassive black holes, and thus, BAL quasars are prime targets for investigating the potential process of luminous quasar feedback on galaxies. We analyzed the rest-UV spectrum of an "overlapping trough" iron low-ionization …
The Formation Height of Millimeter-wavelength Emission in the Solar Chromosphere
Martínez-Sykora, Juan; De Pontieu, Bart; Chintzoglou, Georgios +1 more
In the past few years, the ALMA radio telescope has become available for solar observations. ALMA diagnostics of the solar atmosphere are of high interest because of the theoretically expected linear relationship between the brightness temperature at millimeter wavelengths and the local gas temperature in the solar atmosphere. Key for the interpre…