Examinando por Autor "Cosentino, R."

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SiO emission as a probe of cloud–cloud collisions in infrared dark clouds
(Oxford Academics: Oxford University Press, 2020-09-25) Cosentino, R.; Jiménez Serra, I.; Henshaw, J. D.; Caselli, P.; Viti, S.; Barnes, A. T.; Tan, T. C.; Fontani, F.; Wu, B.; European Research Council (ERC); Ministerio de Economía y Competitividad (MINECO); Henshaw, J. [0000-0001-9656-7682]; Fontani, F. [0000-0003-0348-3418]; Barnes, A. [0000-0003-0410-4504]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Infrared dark clouds (IRDCs) are very dense and highly extincted regions that host the initial conditions of star and stellar cluster formation. It is crucial to study the kinematics and molecular content of IRDCs to test their formation mechanism and ultimately characterize these initial conditions. We have obtained high-sensitivity Silicon Monoxide, SiO(2–1), emission maps towards the six IRDCs, G018.82–00.28, G019.27+00.07, G028.53–00.25, G028.67+00.13, G038.95–00.47, and G053.11+00.05 (cloud A, B, D, E, I, and J, respectively), using the 30-m antenna at the Instituto de Radioastronomía Millimétrica (IRAM30m). We have investigated the SiO spatial distribution and kinematic structure across the six clouds to look for signatures of cloud–cloud collision events that may have formed the IRDCs and triggered star formation within them. Towards clouds A, B, D, I, and J, we detect spatially compact SiO emission with broad-line profiles that are spatially coincident with massive cores. Towards the IRDCs A and I, we report an additional SiO component that shows narrow-line profiles and that is widespread across quiescent regions. Finally, we do not detect any significant SiO emission towards cloud E. We suggest that the broad and compact SiO emission detected towards the clouds is likely associated with ongoing star formation activity within the IRDCs. However, the additional narrow and widespread SiO emission detected towards cloud A and I may have originated from the collision between the IRDCs and flows of molecular gas pushed towards the clouds by nearby H II regions.
Acceso Abierto
The GAPS programme at TNG XXII. The GIARPS view of the extended helium atmosphere of HD 189733 b accounting for stellar activity
(EDP Sciences, 2020-07-07) Guilluy, G.; Andretta, V.; Borsa, F.; Giacobbe, P.; Sozzetti, A.; Covino, E.; Bourrier, V.; Fossati, L.; Bonomo, A. S.; Esposito, M.; Giampapa, M. S.; Harutyunyan, A.; Rainer, M.; Brogi, M.; Bruno, G.; Claudi, R.; Frustagli, G.; Lanza, A. F.; Mancini, L.; Pino, L.; Poretti, E.; Scandariato, G.; Affer, L.; Baffa, C.; Baruffolo, A.; Benatti, S.; Biazzo, K.; Bignamini, A.; Boschin, W.; Carleo, I.; Cecconi, M.; Cosentino, R.; Damasso, M.; Desidera, S.; Falcini, G.; Martínez Fiorenzano, A. F.; Ghedina, A.; González Álvarez, E.; Guerra, J.; Hernández, N.; Leto, G.; Maggio, A.; Malavolta, L.; Maldonado, J.; Micela, G.; Molinari, E.; Nascimbeni, V.; Pagano, I.; Pedani, M.; Piotto, G.; Reiners, A.; Agenzia Spaziale Italiana (ASI); Istituto Nazionale di Astrofisica (INAF); Swiss National Science Foundation (SNSF); European Research Council (ERC); Deutsche Forschungsgemeinschaft (DFG); Claudi, R. [orcid.org/0000-0001-7707-5105]; Leto, G. [orcid.org/0000-0002-0040-5011]; Ghedina, A. [orcid.org/0000-0003-4702-5152]; Pino, L. [orcid.org/0000-0002-1321-8856]; Damaso, M. [orcid.org/0000-0001-9984-4278]; Cosentino, R. [orcid.org/0000-0003-1784-1431]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. Exoplanets orbiting very close to their parent star are strongly irradiated. This can lead the upper atmospheric layers to expand and evaporate into space. The metastable helium (He I) triplet at 1083.3 nm has recently been shown to be a powerful diagnostic to probe extended and escaping exoplanetary atmospheres. Aims. We perform high-resolution transmission spectroscopy of the transiting hot Jupiter HD 189733 b with the GIARPS (GIANO-B + HARPS-N) observing mode of the Telescopio Nazionale Galileo, taking advantage of the simultaneous optical+near infrared spectral coverage to detect He I in the planet’s extended atmosphere and to gauge the impact of stellar magnetic activity on the planetary absorption signal. Methods. Observations were performed during five transit events of HD 189733 b. By comparison of the in-transit and out-of-transit GIANO-B observations, we computed high-resolution transmission spectra. We then used them to perform equivalent width measurements and carry out light-curves analyses in order to consistently gauge the excess in-transit absorption in correspondence with the He I triplet. Results. We spectrally resolve the He I triplet and detect an absorption signal during all five transits. The mean in-transit absorption depth amounts to 0.75 ± 0.03% (25σ) in the core of the strongest helium triplet component. We detect night-to-night variations in the He I absorption signal likely due to the transit events occurring in the presence of stellar surface inhomogeneities. We evaluate the impact of stellar-activity pseudo-signals on the true planetary absorption using a comparative analysis of the He I 1083.3 nm (in the near-infrared) and the Hα (in the visible) lines. Using a 3D atmospheric code, we interpret the time series of the He I absorption lines in the three nights not affected by stellar contamination, which exhibit a mean in-transit absorption depth of 0.77 ± 0.04% (19σ) in full agreement with the one derived from the full dataset. In agreement with previous results, our simulations suggest that the helium layers only fill part of the Roche lobe. Observations can be explained with a thermosphere heated to ~12 000 K, expanding up to ~1.2 planetary radii, and losing ~1 g s−1 of metastable helium. Conclusions. Our results reinforce the importance of simultaneous optical plus near infrared monitoring when performing high-resolution transmission spectroscopy of the extended and escaping atmospheres of hot planets in the presence of stellar activity.