Search Publications
An 'alien' called the Oosterhoff dichotomy?
Rejkuba, M.; Clementini, G.; Ripepi, V. +4 more
Aims. In this Letter we investigate the origin of the Oosterhoff dichotomy in light of recent discoveries related to several ancient merging events of external galaxies with the Milky Way (MW). In particular, we aim to clarify if the subdivision in terms of the Oosterhoff type between Galactic globular clusters (GGCs) and field RR Lyrae (RRLs) can…
JWST imaging of the closest globular clusters: III. Multiple populations along the low-mass main-sequence stars of NGC 6397
Salaris, M.; Apai, D.; Anderson, J. +9 more
Thanks to its exceptional near-infrared photometry, JWST can effectively contribute to the discovery, characterisation, and understanding of multiple stellar populations in globular clusters, especially at low masses where the Hubble Space Telescope (HST) faces limitations. This paper continues the efforts of the JWST GO-1979 programme in explorin…
Merger-driven Growth of Intermediate-mass Black Holes: Constraints from Hubble Space Telescope Imaging of Hyper-luminous X-Ray Sources
Stern, Daniel; Comerford, Julia M.; Barrows, R. Scott +1 more
Hyper-luminous X-ray sources (HLXs) are extragalactic off-nuclear X-ray sources with luminosities exceeding the theoretical limit for accretion onto stellar-mass compact objects. Many HLXs may represent intermediate-mass black holes (IMBHs) deposited in galaxy halos through mergers, and the properties of the stellar cores surrounding HLXs provide …
Revealing faint compact radio jets at redshifts above 5 with very long baseline interferometry
Ghisellini, G.; Giroletti, M.; An, T. +6 more
Context. Over the past two decades, our knowledge of the high-redshift (z > 5) radio quasars has expanded, thanks to dedicated high-resolution very long baseline interferometry (VLBI) observations. Distant quasars provide unique information about the formation and evolution of the first galaxies and supermassive black holes in the Universe. Pow…
Reconstructing Intrinsic Stellar Noise with Stellar Atmospheric Parameters and Chromospheric Activity
Xiang, Maosheng; Bi, Shaolan; Li, Yaguang +9 more
Accurately characterizing the intrinsic stellar photometric noise induced by stellar astrophysics, such as stellar activity, granulation, and oscillations, is of crucial importance for detecting transiting exoplanets. In this study, we investigate the relation between the intrinsic stellar photometric noise, quantified by the Kepler combined diffe…
The galaxy group merger origin of the Cloverleaf odd radio circle system
Zhang, X.; Nandra, K.; Merloni, A. +14 more
Odd radio circles (ORCs) are a newly discovered class of extended faint radio sources of unknown origin. We report the first detection of diffuse X-ray gas at the location of a low-redshift ORC (z = 0.046) known as Cloverleaf ORC. This observation was performed with the XMM-Newton X-ray telescope. The physical extent of the diffuse X-ray emission …
A deep-learning approach to the 3D reconstruction of dust density and temperature in star-forming regions
Klessen, Ralf S.; Testi, Leonardo; Hennebelle, Patrick +8 more
Aims: We introduce a new deep-learning approach for the reconstruction of 3D dust density and temperature distributions from multi-wavelength dust emission observations on the scale of individual star-forming cloud cores (<0.2 pc).
Methods: We constructed a training data set by processing cloud cores from the Cloud Factory simulations…
Relationships Between HCl, H2O, Aerosols, and Temperature in the Martian Atmosphere: 2. Quantitative Correlations
Patel, M. R.; Montmessin, F.; Fedorova, A. A. +15 more
The detection of hydrogen chloride (HCl) in the atmosphere of Mars was among the primary objectives of the ExoMars Trace Gas Orbiter (TGO) mission. Its discovery using the Atmospheric Chemistry Suite mid-infrared channel (ACS MIR) showed a distinct seasonality and possible link to dust activity. This paper is part 2 of a study investigating the li…
Slitless spectrophotometry with forward modelling: Principles and application to measuring atmospheric transmission
Copin, Y.; Le Guillou, L.; Moniez, M. +9 more
Context. In the next decade, many optical surveys will aim to answer the question of the nature of dark energy by measuring its equation-of-state parameter at the per mill level. This requires trusting the photometric calibration of the survey with a precision never reached so far on many sources of systematic uncertainties. The measurement of the…
Revision of the GeV γ-Ray Emission in the Region of HESS J1813-178 with Fermi-LAT
Xin, Yuliang; Guo, Xiaolei
HESS J1813-178 is one of the brightest and most compact TeV γ-ray sources, and whether its γ-ray emission is associated with supernova remnant (SNR), pulsar wind nebula (PWN), or young stellar cluster (YSC) is still under debate. By analyzing the GeV γ-ray data in the field of HESS J1813-178 using 14 yr of PASS 8 data recorded by the Fermi Large A…