Search Publications

The MAGIC project - II. Discovery of two new Galactic lithium-rich Cepheids

Kovtyukh, V.; Lemasle, B.; Kniazev, A. +6 more

We report the discovery of two new lithium-rich Cepheids in the Milky Way (A(Li) ≈ 2.9 dex) among the targets of the MAGIC spectroscopic survey with the Southern African Large Telescope spectrographs. The 6707 Å Li feature is usually not detectable in the atmosphere of Cepheids. Only three Cepheids (two in the Milky Way and one in the Large Magell…

A MUSE study of the inner bulge globular cluster Terzan 9: a fossil record in the Galaxy

Bica, E.; Barbuy, B.; Kamann, S. +5 more

Context. Moderately metal-poor inner bulge globular clusters are relics of a generation of long-lived stars that formed in the early Galaxy. Terzan 9, projected at 4^°_.12 from the Galactic center, is among the most central globular clusters in the Milky Way, showing an orbit which remains confined to the inner 1 kpc.
Aims…

The Mass Dependence of Structure, Star Formation Rate, and Mass Assembly Mode at 0.5 < z < 2.5

Fang, Guanwen; Kong, Xu; Gu, Yizhou +5 more

To investigate the mass dependence of structural transformation and star formation quenching, we construct three galaxy samples using massive (M _* > 10¹⁰ M _⊙) red, green, and blue galaxy populations at 0.5 < z < 2.5 in five 3D-HST/CANDELS fields. The structural parameters, including effective radius (r

Resolving the distance controversy for Sharpless 269. A possible kink in the outer arm

Immer, K.; Reid, M. J.; Quiroga-Nuñez, L. H. +2 more

Context. Sharpless 269 (S 269) is one of a few HII regions in the outer spiral arm of the Milky Way with strong water maser emission. Based on data from the Very Long Baseline Interferometry (VLBI) Exploration of Radio Astrometry (VERA) array, two parallax measurements have been published, which differ by nearly 2σ. Each distance estimate supports…

Evolution of the Extended X-Ray Emission from the PSR B1259-63/LS 2883 Binary in the 2014-2017 Binary Cycle

Kargaltsev, Oleg; Hare, Jeremy; Pavlov, George +1 more

We have performed a series of Chandra X-ray Observatory observations of the gamma-ray binary LS 2883, which is composed of a young pulsar (PSR B1259-63) orbiting a massive Be star with a period of 1236.7 days. The system was observed in five epochs, spanning a range from 352 to 1175 days after the periastron passage on 2014 May 4. The observations…

Multi-line Herschel/HIFI observations of water reveal infall motions and chemical segregation around high-mass protostars

Shipman, R. F.; Braine, J.; van der Tak, F. F. S. +3 more

Context. The physical conditions during high-mass star formation are poorly understood. Outflow and infall motions have been detected around massive protostellar objects, but their dependence on mass, luminosity, and age is unclear. In addition, physical conditions and molecular abundances are often estimated using simple assumptions such as spher…

ALMA observations of massive molecular gas reservoirs in dusty early-type galaxies

Smith, M.; Dunne, L.; Eales, S. +9 more

Unresolved gas and dust observations show a surprising diversity in the amount of interstellar matter in early-type galaxies. Using Atacama Large Millimetre/submillimeter Array (ALMA) observations we resolve the ISM in z ∼ 0.05 early-type galaxies. From a large sample of early-type galaxies detected in the Herschel Astrophysical Terahertz Large Ar…

Does High-density or Mass Help Star Clusters Produce X-Ray Binaries in Star-forming Galaxies?

Chandar, R.; Johns Mulia, P.; Rangelov, B.

It is now widely accepted that many X-ray binaries (XRBs) form in compact star clusters. Therefore, it follows that there may be a link between the properties of star clusters and the production of XRBs. We study the masses and densities of compact clusters with different ages found in the merging Antennae galaxies and in the dwarf starburst NGC 4…

A 183-GHz InP/CMOS-Hybrid Heterodyne-Spectrometer for Spaceborne Atmospheric Remote Sensing

Zhang, Yan; Kim, Yanghyo; James Reck, Theodore +5 more

The GALAH survey: velocity fluctuations in the Milky Way using Red Clump giants

Lewis, Geraint F.; Ting, Yuan-Sen; Wittenmyer, Robert A. +20 more

If the Galaxy is axisymmetric and in dynamical equilibrium, we expect negligible fluctuations in the residual line-of-sight velocity field. Recent results using the APOGEE survey find significant fluctuations in velocity for stars in the mid-plane (|z| <0.25 kpc) out to 5 kpc, suggesting that the dynamical influence of non-axisymmetric features…