The radio jets of SS 433 at millimetre wavelengths

Context. SS 433 is historically a well-known microquasar in the Galaxy that has been deeply studied during the four decades elapsed since its discovery. However, observations at very high radio frequencies with good angular resolution are still very scarce in the literature. The present paper tries to partially fill this gap using archival data of the source obtained with the Atacama Large Millimeter Array (ALMA). Aims. We aim to study the SS 433 jet properties at radio frequencies corresponding to millimetre wavelengths where the synchrotron emitting particles are expected to lose their energy much faster than at lower frequencies of centimetre wavelengths. Results. A resolved view of the SS 433 radio core and jets is presented. In addition to spectral index and magnetic field measurements, we are able to estimate the age of the oldest visible ejecta still radiating significantly at millimetre wavelengths. By combining our findings with those of previous authors at lower frequencies, we confirm that the energy loss of the radiating electrons is dominated by adiabatic expansion instead of synchrotron radiative losses. In addition, we find suggestive evidence for the previously proposed period of slowed expansion within the first months of the ejecta flow, needed to simultaneously match the radiative lifetime observed in the centimetre domain. Our results argue for the need for future coordinated millimetre and centimetre interferometric observations with good time sampling throughout the SS 433 precessional cycle to better understand energetic processes in stellar relativistic jets.Comment: 14 pages, 7 figures, Accepted for publication in Astronomy & Astrophysic

Hints of the photometric period in radial velocity data of the X-ray binary HD 3191 with the Joan Oró telescope

We focus our attention on the newly proposed X-ray binary system HD 3191 whose nature still lacks dynamical confirmation and accurate orbital parameters. The positional agreement of this object with a flaring gamma-ray source was the original motivation of this work, although the present chances of association are reduced. A long-term spectroscopic monitoring of HD3191 was conducted using the 1-m class, robotic, Joan Oró telescope at the Observatori Astronòmic del Montsec facilities, located in the pre-Pyrenees mountains 140 km away from Barcelona. The Doppler measurements suggest an agreement with the previously reported 16.09 d photometric period, as expected. We also present a very preliminary radial velocity curve based on a circular orbit solution that hints to a low velocity amplitude. Nevertheless, the instrumental limitations of our data render necessary to carry out improved spectroscopic observations to better discriminate among the nature of the compact companion.Funding for open access publishing: Universidad de Jaén/ CBUA. This work was mainly supported by grant PID2019-105510GBC32/ AEI/10.13039/501100011033 from State Agency for Research of the Spanish Ministry of Science and Innovation entitled High energy sources with outflows at different scales: observation of galactic sources. We also acknowledge support by Consejería de Economía, Innovación, Ciencia y Empleo of Junta de Andalucía as research group FQM-322, as well as FEDER funds. JMP acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science and Innovation under grant PID2019-105510GB-C31 and through the Unit of Excellence María de Maeztu 2020-2023 award to the Institute of Cosmos Sciences (CEX2019-000918-M), and by the Catalan DEC grant 2017 SGR 643

Possible Association of Two Stellar Bowshocks with Unidentified <i>Fermi</i> Sources

The bowshocks of runaway stars had been theoretically proposed as gamma-ray sources. However, this hypothesis has not been confirmed by observations to date. In this paper, we present two runaway stars (λ Cep and LS 2355) whose bowshocks are coincident with the unidentified Fermi gamma-ray sources 3FLG J2210.1+5925 and 3FGL J1128.7-6232, respectively. After performing a cross-correlation between different catalogs at distinct wavelengths, we found that these bowshocks are the most peculiar objects in the Fermi position ellipses. Then we computed the inverse Compton emission and fitted the Fermi data in order to test the viability of both runaway stars as potential counterparts of the two high-energy sources. We obtained very reasonable values for the fitted parameters of both stars. We also evaluated the possibility for the source 3FGL J1128.7-6232, which is positionally coincident with a H II region, to be the result of background cosmic-ray protons interacting with the matter of the cloud, as well as the probability of a pure chance association. We conclude that the gamma rays from these Fermi sources might be produced in the bowshocks of the considered runaway stars. In such a case, these would be the first sources of this class ever detected at gamma rays.Facultad de Ciencias Astronómicas y Geofísica

A systematic cross-search for radio/infrared counterparts of XMM-Newton sources

We present a catalog of cross-correlated radio, infrared and X-ray sources using a very restrictive selection criteria with an IDL-based code developed by us. The significance of the observed coincidences was evaluated through Monte Carlo simulations of synthetic sources following a well-tested protocol. We found 3320 coincident radio/X-ray sources with a high statistical significance characterized by the sum of error-weighted coordinate differences. For 997 of them, 2MASS counterparts were found. The percentage of chance coincidences is less than 1%. X-ray hardness ratios of well-known populations of objects were used to provide a crude representation of their X-ray spectrum and to make a preliminary diagnosis of the possible nature of unidentified X-ray sources. The results support the fact that the X-ray sky is largely dominated by Active Galactic Nuclei at high galactic latitudes (|b|≥10°). At low galactic latitudes (|b|≤10°) most of unidentified X-ray sources (∼94%) lie at |b|≤2°. This result suggests that most of the unidentified sources found toward the Milky Way plane are galactic objects. Well-known and unidentified sources were classified in different tables with their corresponding radio/infrared and X-ray properties. These tables are intended as a useful tool for researchers interested in particular identifications.Facultad de Ciencias Astronómicas y GeofísicasInstituto Argentino de Radioastronomí

Propuesta de gestión para la integración de procesos ambulatorios en un Servicio de Neurología

El objetivo del presente documento es servir como Trabajo de Fin de Máster. En él se verán recogidos parte de los conocimientos adquiridos durante el Máster Universitario en Dirección y Gestión Sanitaria realizado en el curso 2016/2017 en la Universidad Internacional de La Rioja. Partiendo del análisis de funcionamiento de un Servicio de Neurología de un Hospital de tercer nivel, se plantea un modelo de gestión de las consultas ambulatorias situadas en un Centro de Especialidades Periférico en el que, mediante la coordinación y la integración con Atención Primaria (AP), se facilite una mejor atención a determinados pacientes en el ámbito ambulatorio, al tiempo que se disminuye la dependencia del medio hospitalario. La demanda de atención sanitaria en general, y de Atención Especializada (AE) en particular, sigue un camino ascendente que, a pesar del aumento de las plantillas y los recursos disponibles en nuestro medio, se hace insuficiente, generando listas de espera en los hospitales que, por sí mismas, suponen un deterioro debido a la demora en el diagnóstico y el tratamiento. En Neurología se suman otra serie de características que le son propias. De especial importancia, asociado a la mayor esperanza de vida, es el aumento exponencial de enfermedades neurodegenerativas, especialmente demencias y trastornos del movimiento. Un problema añadido es la preocupación que suscita, en parte de la población, la presencia de síntomas leves que pudieran ser el inicio de dichas enfermedades. De poco sirve proveer de una atención de alta calidad en cuanto a medios y tiempo a una parte de los pacientes, si se convive con una demora excesiva para la misma. Por otro lado, la asistencia hospitalaria conlleva un mayor coste y, en ese aspecto, puede ser menos eficiente en determinados procesos que puedan beneficiarse de programas integrados con AP. Planteo como útil la existencia de un “nivel intermedio” entre Atención Primaria y la atención especializada que proporciona el Hospital, que permita una adecuada selección de los pacientes que precisan de esta última, al tiempo que trabaja de forma integrada con AP, ofreciendo una respuesta rápida y facilitando una atención de calidad al paciente con enfermedades neurológicas en el medio ambulatorio extrahospitalario. Es en este lugar dónde quiero situar una Unidad de Neurología Ambulatoria de un Centro de Especialidades (UNACE)

A runaway T Tauri star leaving an extended trail

Aims. We address the problem of young stellar objects that are found too far away from possible star formation sites. Different mechanisms have been proposed before to explain this unexpected circumstance. The idea of high-velocity protostars is one of these mechanisms, although observational support is not always easy to obtain. We aim to shed light on this issue after the serendipitous discovery of a related stellar system. Methods. Following the inspection of archival infrared data, a peculiar anonymous star was found that apparently heads a long tail that resembles a wake-like feature. We conducted a multiwavelength analysis including photometry, astrometry, and spectroscopy. Together with theoretical physical considerations, this approach provided a reasonable knowledge of the stellar age and kinematic properties, together with compelling indications that the extended feature is indeed the signature of a high-velocity, or runaway, newborn star. Results. Our main result is the discovery of a low-mass young stellar object that fits the concept of a runaway T Tauri star that was hypothesized several decades ago. In this peculiar star, nicknamed UJT-1, the interaction of the stellar wind with the surrounding medium becomes extreme. Under reasonable assumptions, this unusual degree of interaction has the potential to encode the mass-loss history of the star on timescales of several ∼105 years

Search for new stellar sources of gamma-rays

We review and report about the present status of our search for gamma-ray binaries, microquasars, and new kinds of gamma-ray source associated with star forming regions in the Galaxy. The search is being carried out using cross-identification techniques applied to public databases and archives. A few promising candidates have been so far identified. These include the emission line star VES 737 and the central cluster of the Monoceros R2 star forming region. The observational data supporting the proposed associations is shortly presented and discussed

Orbital and sub-orbital period determination of the candidate high-mass X-ray binary HD 3191

The final aim of this paper is to expand the sparse group of X-ray binaries with gamma-ray counterparts as laboratories to study high-energy processes under physical conditions that periodically repeat. A follow-up of a candidate system has been carried out. We applied both photometric and spectroscopic techniques in the optical domain together with a period analysis using the phase dispersion minimization and CLEAN methods. A tentative period search was also conducted in the gamma-ray domain. Our main result is having established the binary nature of the optical star and X-ray emitter HD 3191 towards the Fermi gamma-ray source 4FGL J0035.8+6131, the last one proposed to be associated with a blazar of an unknown type. An orbital period close to 16 days is reported for HD 3191 together with a likely rotation, or pulsation, period of about 0.6 d. Although no convincing evidence for the orbital cycle has been found in the Fermi light curve up to now, the confirmed presence of a high-mass X-ray binary towards 4FGL J0035.8+6131 now strengthens the need for caution about its true nature.Comment: Accepted for publication in Astronomy & Astrophysic

Possible Association of Two Stellar Bowshocks with Unidentified Fermi Sources

The bowshocks of runaway stars had been theoretically proposed as gamma-ray sources. However, this hypothesis has not been confirmed by observations to date. In this paper, we present two runaway stars (λ Cep and LS 2355) whose bowshocks are coincident with the unidentified Fermi gamma-ray sources 3FLG J2210.1+5925 and 3FGL J1128.7-6232, respectively. After performing a cross-correlation between different catalogs at distinct wavelengths, we found that these bowshocks are the most peculiar objects in the Fermi position ellipses. Then we computed the inverse Compton emission and fitted the Fermi data in order to test the viability of both runaway stars as potential counterparts of the two high-energy sources. We obtained very reasonable values for the fitted parameters of both stars. We also evaluated the possibility for the source 3FGL J1128.7-6232, which is positionally coincident with a H ii region, to be the result of background cosmic-ray protons interacting with the matter of the cloud, as well as the probability of a pure chance association. We conclude that the gamma rays from these Fermi sources might be produced in the bowshocks of the considered runaway stars. In such a case, these would be the first sources of this class ever detected at gamma rays.Fil: Sánchez Ayaso, Estrella. Universidad de Jaén; EspañaFil: Del Valle, María V.. Universitat Potsdam; AlemaniaFil: Martí, Josep. Universidad de Jaén; EspañaFil: Romero, Gustavo Esteban. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Luque Escamilla, Pedro L.. Universidad de Jaén; Españ

A blazar as the likely counterpart to 4FGL J0647.7−4418 instead of a gamma-ray binary

The persistent gamma-ray source 4FGL J0647.7−4418 is tentatively associated in the latest Fermi catalogue with the subdwarf O-type X-ray binary HD 49798. However, an active galactic nucleus (AGN) candidate is also mentioned as an alternative identification in updated versions of the catalogue accompanying paper. If the first association were correct, this would add HD 49798 to the handful of currently known gamma-ray binaries, and therefore represent a significant breakthrough not only because of a new member addition, but also because of the apparent white dwarf companion in this system. Despite these perspectives, here, we show that the stellar association is likely wrong and that the proposed AGN object, well inside the Fermi 95 per cent confidence ellipse, is a more conceivable counterpart candidate to the Fermi source due to its strong blazar similarities.This work was supported by the Agencia Estatal de Investigación grants AYA2016-76012-C3-1-P and AYA2016-76012-C3-3-P from the Spanish Ministerio de Economía y Competitividad (MINECO), by Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía under research group FQM-322, by grant MDM-2014-0369 of the Institute of Cosmos Sciences (ICCUB, Unidad de Excelencia ‘María de Maeztu’), and by the Catalan DEC grant 2017 SGR 643, as well as Fondo Europeo de Desarrollo Regional (FEDER) funds. RC acknowledges support from National Aeronautics and Space Administration (NASA) Fermi grant NNX15AU83G.Peer reviewe