RAS_WEB (Page 2,272)

SS 433: flares in H alpha, GRAVITY observations & L2 ejection. (arXiv:2103.15782v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Bowler_M/0/1/0/all/0/1">M. G. Bowler</a> Abstract The microquasar SS 433 exhibits in H alpha intermittent flares, Doppler shifted to both the red and the blue. The mean remembers the orbital phase of the compact object. I show that the flares are not intermittent sightings of an accretion disk; rather, plasma must be expelled through the L2 point, thus remembering the phase of the orbit as it invades the space beyond the system. That space has been mapped with GRAVITY observations of a similar flare, revealing a strong rotation component. Abstract The microquasar SSRead More →

The InfraRed Imaging Spectrograph (IRIS) for TMT: photometric characterization of anisoplanatic PSFs and testing of PSF-Reconstruction via AIROPA. (arXiv:2103.15779v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Rundquist_N/0/1/0/all/0/1">Nils Rundquist</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wright_S/0/1/0/all/0/1">Shelley A. Wright</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schoeck_M/0/1/0/all/0/1">Matthias Schoeck</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Surya_A/0/1/0/all/0/1">Arun Surya</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lu_J/0/1/0/all/0/1">Jessica Lu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Turri_P/0/1/0/all/0/1">Paolo Turri</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chapin_E/0/1/0/all/0/1">Edward L. Chapin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chisholm_E/0/1/0/all/0/1">Eric Chisholm</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dod_T/0/1/0/all/0/1">Tuan Dod</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dunn_J/0/1/0/all/0/1">Jennifer Dunn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ghez_A/0/1/0/all/0/1">Andrea Ghez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hayano_Y/0/1/0/all/0/1">Yutaka Hayano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Johnson_C/0/1/0/all/0/1">Chris Johnson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Larkin_J/0/1/0/all/0/1">James E. Larkin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Riddle_R/0/1/0/all/0/1">Reed L. Riddle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sohn_J/0/1/0/all/0/1">Ji Man Sohn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Suzuki_R/0/1/0/all/0/1">Ryuji Suzuki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Walth_G/0/1/0/all/0/1">Gregory Walth</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zonca_A/0/1/0/all/0/1">Andrea Zonca</a> The InfraRed Imaging Spectrograph (IRIS) is a first-light instrument for the Thirty Meter Telescope (TMT) that will be used to sample the correctedRead More →

Effects of Bound Diprotons and Enhanced Nuclear Reaction Rates on Stellar Evolution. (arXiv:2103.15744v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Adams_F/0/1/0/all/0/1">Fred C. Adams</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Howe_A/0/1/0/all/0/1">Alex R. Howe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Grohs_E/0/1/0/all/0/1">Evan Grohs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fuller_G/0/1/0/all/0/1">George M. Fuller</a> Deuterium represents the only bound isotope in the universe with atomic mass number $A=2$. Motivated by the possibility of other universes, where the strong force could be stronger, this paper considers the effects of bound diprotons and dineutrons on stars. We find that the existence of additional stable nuclei with $A=2$ has relatively modest effects on the universe. Previous work indicates that Big Bang Nucleosynthesis (BBN) produces more deuterium, but does not lead to catastrophic heavyRead More →

Did NANOGrav see a signal from primordial black hole formation?. (arXiv:2009.07832v4 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Vaskonen_V/0/1/0/all/0/1">Ville Vaskonen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Veermae_H/0/1/0/all/0/1">Hardi Veerm&#xe4;e</a> We show that the recent NANOGrav result can be interpreted as a stochastic gravitational wave signal associated to formation of primordial black holes from high-amplitude curvature perturbations. The indicated amplitude and power of the gravitational wave spectrum agrees well with formation of primordial seeds for supermassive black holes. We show that the recent NANOGrav result can be interpreted as a stochastic gravitational wave signal associated to formation of primordial black holes from high-amplitude curvature perturbations. The indicated amplitude and power of the gravitational wave spectrum agreesRead More →

A transmission spectrum of the planet candidate WD 1856+534 b and a lower limit to its mass. (arXiv:2103.15720v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Alonso_R/0/1/0/all/0/1">R. Alonso</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rodriguez_Gil_P/0/1/0/all/0/1">P. Rodr&#xed;guez-Gil</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Izquierdo_P/0/1/0/all/0/1">P. Izquierdo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Deeg_H/0/1/0/all/0/1">H.J. Deeg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lodieu_N/0/1/0/all/0/1">N. Lodieu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cabrera_Lavers_A/0/1/0/all/0/1">A. Cabrera-Lavers</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hollands_M/0/1/0/all/0/1">M.A. Hollands</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Perez_Toledo_F/0/1/0/all/0/1">F.M. P&#xe9;rez-Toledo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Castro_Rodriguez_N/0/1/0/all/0/1">N. Castro-Rodr&#xed;guez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reverte_Paya_D/0/1/0/all/0/1">D. Reverte-Pay&#xe1;</a> The cool white dwarf WD 1856+534 was found to be transited by a Jupiter-sized object with a mass at or below 14 M$_{rm{Jup}}$. We used the GTC telescope to obtain and analyse photometry and low resolution spectroscopy of six transits of WD 1856+534 b, with the intention to derive the slope of the transmission spectrum, towardsRead More →

Boson stars in Palatini $f(mathcal{R})$ gravity. (arXiv:2103.15705v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Maso_Ferrando_A/0/1/0/all/0/1">Andreu Mas&#xf3;-Ferrando</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Sanchis_Gual_N/0/1/0/all/0/1">Nicolas Sanchis-Gual</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Font_J/0/1/0/all/0/1">Jos&#xe9; A. Font</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Olmo_G/0/1/0/all/0/1">Gonzalo J. Olmo</a> We explore equilibrium solutions of spherically symmetric boson stars in the Palatini formulation of $f(mathcal{R})$ gravity. We account for the modifications introduced in the gravitational sector by using a recently established correspondence between modified gravity with scalar matter and general relativity with modified scalar matter. We focus on the quadratic theory $f(mathcal{R})=R+xi R^2$ and compare its solutions with those found in general relativity, exploring both positive and negative values of the coupling parameter $xi$. As matter source, a complex, massive scalar field withRead More →

HST PanCET program: Non-detection of atmospheric escape in the warm Saturn-sized planet WASP-29 b. (arXiv:2103.15688v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Santos_L/0/1/0/all/0/1">L. A. dos Santos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bourrier_V/0/1/0/all/0/1">V. Bourrier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ehrenreich_D/0/1/0/all/0/1">D. Ehrenreich</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanz_Forcada_J/0/1/0/all/0/1">J. Sanz-Forcada</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lopez_Morales_M/0/1/0/all/0/1">M. L&#xf3;pez-Morales</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sing_D/0/1/0/all/0/1">D. K. Sing</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Munoz_A/0/1/0/all/0/1">A. Garc&#xed;a Mu&#xf1;oz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Henry_G/0/1/0/all/0/1">G. W. Henry</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lavvas_P/0/1/0/all/0/1">P. Lavvas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Etangs_A/0/1/0/all/0/1">A. Lecavelier des Etangs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mikal_Evans_T/0/1/0/all/0/1">T. Mikal-Evans</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vidal_Madjar_A/0/1/0/all/0/1">A. Vidal-Madjar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wakeford_H/0/1/0/all/0/1">H. R. Wakeford</a> (Abridged) Short-period gas giant exoplanets are susceptible to intense atmospheric escape due to their large scale heights and strong high-energy irradiation. This process is thought to occur ubiquitously, but to date we have only detected direct evidence of atmospheric escape in hotRead More →

Venus upper atmosphere revealed by a GCM: II. Model validation with temperature and density measurements. (arXiv:2103.15649v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Gilli_G/0/1/0/all/0/1">Gabriella Gilli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Navarro_T/0/1/0/all/0/1">Thomas Navarro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lebonnois_S/0/1/0/all/0/1">Sebastien Lebonnois</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Quirino_D/0/1/0/all/0/1">Diogo Quirino</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Silva_V/0/1/0/all/0/1">Vasco Silva</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stolzenbach_A/0/1/0/all/0/1">Aurelien Stolzenbach</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lefevre_F/0/1/0/all/0/1">Franck Lef&#xe8;vre</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schubert_G/0/1/0/all/0/1">Gerald Schubert</a> An improved high-resolution ground-to-thermosphere version of the Institut Pierre-Simon Laplace (IPSL) Venus General Circulation Model (VGCM), including non-orographic gravity waves (GW) parameterization and fine-tuned non-LTE parameters, is presented here. We focus on the validation of the model built from a collection of data mostly from Venus Express experiments and coordinated ground-based telescope campaigns, in the upper mesosphere/lower thermosphere of Venus. These simulations result inRead More →

Modelling the evolution of the Sun’s open and total magnetic flux. (arXiv:2103.15603v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Krivova_N/0/1/0/all/0/1">N. A. Krivova</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Solanki_S/0/1/0/all/0/1">S. K. Solanki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hofer_B/0/1/0/all/0/1">B. Hofer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wu_C/0/1/0/all/0/1">C.-J. Wu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Usoskin_I/0/1/0/all/0/1">I. G. Usoskin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cameron_R/0/1/0/all/0/1">R. Cameron</a> Solar activity in all its varied manifestations is driven by the magnetic field. Particularly important for many purposes are two global quantities, the Sun’s total and open magnetic flux, which can be computed from sunspot number records using models. Such sunspot-driven models, however, do not take into account the presence of magnetic flux during grand minima, such as the Maunder minimum. Here we present a major update of a widely usedRead More →

Artificial Neural Network classification of asteroids in the M1:2 mean-motion resonance with Mars. (arXiv:2103.15586v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Carruba_V/0/1/0/all/0/1">V. Carruba</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aljbaae_S/0/1/0/all/0/1">S. Aljbaae</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Domingos_R/0/1/0/all/0/1">R. C. Domingos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Barletta_W/0/1/0/all/0/1">W. Barletta</a> Artificial neural networks (ANN) have been successfully used in the last years to identify patterns in astronomical images. The use of ANN in the field of asteroid dynamics has been, however, so far somewhat limited. In this work we used for the first time ANN for the purpose of automatically identifying the behaviour of asteroid orbits affected by the M1:2 mean-motion resonance with Mars. Our model was able to perform well above 85% levels for identifying imagesRead More →

Modeling the fast optical transient SN 2019bkc/ATLAS19dqr with a central engine and implication for its origin. (arXiv:2103.15576v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Zheng_J/0/1/0/all/0/1">Jian-He Zheng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yu_Y/0/1/0/all/0/1">Yun-Wei Yu</a> Modern wide-field high-cadence surveys have revealed the significant diversity of optical transient phenomena in their luminosity and timescale distributions, which led to the discovery of some mysterious fast optical transients (FOTs). These FOTs can usually rise and decline remarkably in a timescale of a few days to weeks, which are obviously much rapider than ordinary supernovae. SN 2019bkc/ATLAS19dqr is one of the fastest detected FOTs so far and, meanwhile, it was found to be un-associated with a host galaxy. These discoveriesRead More →

Search for neutrinos from the tidal disruption events AT2019dsg and AT2019fdr with the ANTARES telescope. (arXiv:2103.15526v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Collaboration_ANTARES/0/1/0/all/0/1">ANTARES Collaboration</a>: <a href="http://arxiv.org/find/astro-ph/1/au:+Albert_A/0/1/0/all/0/1">A. Albert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Alves_S/0/1/0/all/0/1">S. Alves</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Andre_M/0/1/0/all/0/1">M. Andr&#xe9;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anghinolfi_M/0/1/0/all/0/1">M. Anghinolfi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anton_G/0/1/0/all/0/1">G. Anton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ardid_M/0/1/0/all/0/1">M. Ardid</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aubert_J/0/1/0/all/0/1">J.-J. Aubert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aublin_J/0/1/0/all/0/1">J. Aublin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baret_B/0/1/0/all/0/1">B. Baret</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Basa_S/0/1/0/all/0/1">S. Basa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Belhorma_B/0/1/0/all/0/1">B. Belhorma</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bendahman_M/0/1/0/all/0/1">M. Bendahman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Benfenati_F/0/1/0/all/0/1">F. Benfenati</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bertin_V/0/1/0/all/0/1">V. Bertin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Biagi_S/0/1/0/all/0/1">S. Biagi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bissinger_M/0/1/0/all/0/1">M. Bissinger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boumaaza_J/0/1/0/all/0/1">J. Boumaaza</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bouta_M/0/1/0/all/0/1">M. Bouta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bouwhuis_M/0/1/0/all/0/1">M.C. Bouwhuis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Branzas_H/0/1/0/all/0/1">H. Br&#xe2;nza&#x15f;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bruijn_R/0/1/0/all/0/1">R. Bruijn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brunner_J/0/1/0/all/0/1">J. Brunner</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Busto_J/0/1/0/all/0/1">J. Busto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Caiffi_B/0/1/0/all/0/1">B. Caiffi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Capone_A/0/1/0/all/0/1">A. Capone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Caramete_L/0/1/0/all/0/1">L. Caramete</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carr_J/0/1/0/all/0/1">J. Carr</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carretero_V/0/1/0/all/0/1">V. Carretero</a>, <aRead More →