Search Publications
The Dragonfly Galaxy. II. ALMA unveils a triple merger and gas exchange in a hyper-luminous radio galaxy at z = 2
Villar-Martín, M.; Seymour, N.; Nesvadba, N. +9 more
The Dragonfly Galaxy (MRC 0152-209), at redshift z ~ 2, is one of the most vigorously star-forming radio galaxies in the Universe. What triggered its activity? We present ALMA Cycle 2 observations of cold molecular CO(6-5) gas and dust, which reveal that this is likely a gas-rich triple merger. It consists of a close double nucleus (separation ~4 …
Testing the homogeneity of the Universe using gamma-ray bursts
Li, Ming-Hua; Lin, Hai-Nan
Aims: The discovery of a statistically significant clustering in the distribution of gamma-ray bursts (GRBs) has recently been reported. Given that the cluster has a characteristic size of 2000-3000 Mpc and a redshift between 1.6 ≤ z ≤ 2.1, it has been claimed that this structure is incompatible with the cosmological principle of homogeneity …
Leptonic origin of the 100 MeV γ-ray emission from the Galactic centre
Walter, R.; Chernyakova, M.; Malyshev, D. +1 more
Context. The Galactic centre is a bright γ-ray source with the GeV-TeV band spectrum composed of two distinct components in the 1-10 GeV and 1-10 TeV energy ranges. The nature of these two components is not clearly understood.
Aims: We investigate the γ-ray properties of the Galactic centre to clarify the origin of the observed emission.
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Gaia astrometry for stars with too few observations. A Bayesian approach
Michalik, Daniel; Lindegren, Lennart; Hobbs, David +1 more
Context. The astrometric solution for Gaia aims to determine at least five parameters for each star, representing its position, parallax, and proper motion, together with appropriate estimates of their uncertainties and correlations. This requires at least five distinct observations per star. In the early data reductions the number of observations…
Gamma-ray activity of Seyfert galaxies and constraints on hot accretion flows
Szanecki, Michał; Niedźwiecki, Andrzej; Xie, Fu-Guo +1 more
Aims: We check how the Fermi/LAT data constrain the physics of hot accretion flows that are most likely present in low-luminosity AGNs.
Methods: Using a precise model of emission from hot flows, we studied the flow γ-ray emission resulting from proton-proton interactions. We explored the dependence of the γ-ray luminosity on the accretio…
Disentangling the jet emission from protostellar systems. The ALMA view of VLA1623
Codella, C.; van Dishoeck, E. F.; Bruderer, S. +4 more
Context. High-resolution studies of class 0 protostars represent the key to constraining protostar formation models. VLA16234-2417 represents the prototype of class 0 protostars, and it has been recently identified as a triple non-coeval system.
Aims: We aim at deriving the physical properties of the jets in VLA16234-2417 using tracers of sho…
NGC 6139: a normal massive globular cluster, or a first-generation dominated cluster? Clues from the light elements
Bragaglia, A.; D'Orazi, V.; Sneden, C. +5 more
Information on globular clusters (GC) formation mechanisms can be gathered by studying the chemical signature of the multiple populations that compose these stellar systems. In particular, we investigate the anti-correlations among O, Na, Al, and Mg to explore the influence of cluster mass and environment on GCs in the Milky Way and in extragalact…
MIARMA: A minimal-loss information method for filling gaps in time series. Application to CoRoT light curves
Garrido, R.; Suárez, J. C.; Pascual-Granado, J.
Context. Gaps in time series cause spurious frequencies in the power spectra. In light curves of pulsating stars, this hampers identifying the theoretical oscillation modes. When these gaps are smaller than the total time span, the commonly used approach to overcome these difficulties involves linear interpolation. The original frequency content o…
SHAPEMOL: a 3D code for calculating CO line emission in planetary and protoplanetary nebulae. Detailed model-fitting of the complex nebula NGC 6302
Santander-García, M.; Bujarrabal, V.; Steffen, W. +1 more
Context. Modern instrumentation in radioastronomy constitutes a valuable tool for studying the Universe: ALMA has reached unprecedented sensitivities and spatial resolution, while Herschel/HIFI has opened a new window (most of the sub-mm and far-infrared ranges are only accessible from space) for probing molecular warm gas (~50-1000 K). On the oth…
Cosmological constraints from the observed angular cross-power spectrum between Sunyaev-Zel'dovich and X-ray surveys
Aghanim, N.; Diego, J. M.; Douspis, M. +3 more
We present the first detection of the cross-correlation angular power spectrum between the thermal Sunyaev-Zel'dovich (tSZ) effect and the X-ray emission over the full sky. The tSZ effect and X-rays are produced by the same hot gas within groups and clusters of galaxies, which creates a naturally strong correlation between them that can be used to…