Search Publications
The behaviour of lithium at high metallicity in the Milky Way. Selection effects in the samples and the possible role of atomic diffusion
de Laverny, P.; Charbonnel, C.; Prantzos, N. +1 more
Aims: We revisit large spectroscopic data sets for field stars from the literature to derive the upper Li envelope in the high metallicity regime in our Galaxy.
Methods: We take advantage of Gaia EDR3 data and state-of-the-art stellar models to precisely determine the position of the sample dwarf stars in the Hertzsprung-Russell diagram.…
Distance and Mass of the NGC 253 Galaxy Group
Anand, Gagandeep S.; Shaya, Edward J.; Tully, R. Brent +2 more
Two dwarf galaxies, WOC2017-07 and PGC 704814, located in the vicinity of the nearby luminous spiral galaxy NGC 253 were observed with the Advanced Camera for Surveys on the Hubble Space Telescope. Their distances of 3.62 ± 0.18 Mpc and 3.66 ± 0.18 Mpc were derived using the tip of the red giant branch method. These distances are consistent with t…
First MATISSE L-band observations of HD 179218. Is the inner 10 au region rich in carbon dust particles?
Waters, L. B. F. M.; Meisenheimer, K.; Augereau, J. -C. +58 more
Context. Carbon is one of the most abundant components in the Universe. While silicates have been the main focus of solid phase studies in protoplanetary discs (PPDs), little is known about the solid carbon content especially in the planet-forming regions (~0.1-10 au). Fortunately, several refractory carbonaceous species present C-H bonds (such as…
Precision of the Chinese Space Station Telescope (CSST) stellar radial velocities
Yuan, Hai-Bo; Sun, Yang; Deng, Ding-Shan
The Chinese Space Station Telescope (CSST) spectroscopic survey plans to deliver high-quality low-resolution (R > 200) slitless spectra for hundreds of millions of targets down to a limiting magnitude of about 21 mag, covering a large survey area (17 500 deg2) and a wide wavelength range (255-1000 nm by three bands GU, GV, and GI). I…
Photoionisation modelling of the X-ray emission line regions within the Seyfert 2 AGN NGC 1068
Bianchi, S.; Mehdipour, M.; Behar, E. +4 more
Aims: We investigate the photoionised X-ray emission line regions (ELRs) within the Seyfert 2 galaxy NGC 1068 to determine if there are any characteristic changes between observations taken 14 years apart.
Methods: We compared XMM-Newton observations collected in 2000 and 2014, simultaneously fitting the reflection grating spectrometer a…
New Families in our Solar Neighborhood: Applying Gaussian Mixture Models for Objective Classification of Structures in the Milky Way and in Simulations
Faucher-Giguère, Claude-André; Sharma, Sanjib; Bonaca, Ana +10 more
The standard picture of galaxy formation motivates the decomposition of the Milky Way into 3-4 stellar populations with distinct kinematic and elemental abundance distributions: the thin disk, thick disk, bulge, and stellar halo. To test this idea, we construct a Gaussian mixture model (GMM) for both simulated and observed stars in the solar neigh…
Observations of compact sources in galaxy clusters using MUSTANG2
Sarazin, Craig L.; Hilton, Matt; Sifón, Cristóbal +26 more
Compact sources can cause scatter in the scaling relationships between the amplitude of the thermal Sunyaev-Zel'dovich Effect (tSZE) in galaxy clusters and cluster mass. Estimates of the importance of this scatter vary - largely due to limited data on sources in clusters at the frequencies at which tSZE cluster surveys operate. In this paper, we p…
New X-ray observations of the hot subdwarf binary HD 49798/RX J0648.0-4418
Rauch, T.; Tiengo, A.; Mereghetti, S. +7 more
HD 49798/RX J0648.0-4418 is the only confirmed X-ray binary in which the mass donor is a hot subdwarf star of O spectral type and, most likely, it contains a massive white dwarf (1.28 ± 0.05 M⊙) with a very fast spin period of 13.2 s. Here, we report the results of new XMM-Newton pointings of this peculiar binary, carried out in 2018 an…
Extreme relativistic reflection in the active galaxy ESO 033-G002
Harrison, F. A.; Stern, D.; Fabian, A. C. +13 more
We present the first high signal-to-noise broad-band X-ray spectrum of the radio-quiet type-2 Seyfert ESO 033-G002, combining data from XMM-Newton and NuSTAR. The nuclear X-ray spectrum is complex, showing evidence for both neutral and ionized absorption, as well as reflection from both the accretion disc and more distant material, but our broad-b…
Detection of millihertz quasi-periodic oscillations in the X-Ray binary 1RXS J180408.9-342058
Galloway, Duncan K.; Chou, Yi; Hsieh, Hung-En +2 more
Millihertz quasi-periodic oscillations (mHz QPOs) observed in neutron-star low-mass X-ray binaries (NS LMXBs) are generally explained as marginally stable thermonuclear burning on the neutron star surface. We report the discovery of mHz QPOs in an XMM-Newton observation of the transient 1RXS J180408.9-342058, during a regular bursting phase of its…