Spitzer observations of the HH 1/2 system. The discovery of the counterjet

We present unpublished Spitzer IRAC observations of the HH 1/2 young stellar outow processed with a high angular resolution deconvolution algorithm, that produces sub-arcsecond (~ 0.6 - 0.8”) images. In the resulting mid-infrared images, the optically invisible counterjet is detected for the first time. The counterjet is approximately half as bright as the jet at 4.5 µm (the IRAC band that best traces young stellar outows) and has a length of ~ 10”. The NW optical jet itself can be followed back in the mid-IR to the position of the exciting VLA 1 source. An analysis of the IRAC colors indicates that the jet/counterjet emission is dominated by collisionally excited H_2 pure rotational lines arising from a medium with a neutral Hydrogen gas density of ~ 1000-2000 cm^(-3) and a temperature ~ 1500 K. The observed jet/counterjet brightness asymmetry is consistent with an intrinsically symmetric outow with extinction from a dense, circumstellar structure of ~ 6” size (along the outow axis), and with a mean visual extinction, A_V ~ 11 mag

New Variable Jet Models for HH 34

We consider newly derived proper motions of the HH 34 jet to reconstruct the evolution of this outflow. We first extrapolate ballistic trajectories for the knots (starting from their present-day positions and velocities) and find that at ~1000 yr in the future most of them will merge to form a larger-mass structure. This mass structure will be formed close to the present-day position of the HH 34S bow shock. We then carry out a fit to the ejection velocity versus time reconstructed from the observed proper motions (assuming that the past motion of the knots was ballistic) and use this fit to compute axisymmetric jet simulations. We find that the intensity maps predicted from these simulations do indeed match reasonably well the [S II] structure of HH 34 observed in Hubble Space Telescope images

Beta decays with momentum space Majorana spinors

We construct and apply to beta decays a truly neutral local quantum field that is entirely based upon momentum space Majorana spinors. We make the observation that theory with momentum space Majorana spinors of real C parities is equivalent to Dirac's theory. For imaginary C parities, the neutrino mass can drop from the single beta decay trace and reappear in 0\nu \beta \beta, a curious and in principle experimentally testable signature for a non-trivial impact of Majorana framework in experiments with polarized sources.Comment: 7 pages, 1 figure; needs svjour.cls, svepj.cl

Proper Motions of Young Stellar Outflows in the Mid-Infrared with Spitzer. II. HH 377/Cep E

We have used multiple mid-infrared observations at 4.5 micron obtained with the Infrared Array Camera, of the compact (~1.4 arcmin) young stellar bipolar outflow Cep E to measure the proper motion of its brightest condensations. The images span a period of ~6 yr and have been reprocessed to achieve a higher angular resolution (~0.8 arcsec) than their normal beam (2 arcsec). We found that for a distance of 730 pc, the tangential velocities of the North and South outflow lobes are 62+/-29 and 94+/-6 km/s respectively, and moving away from the central source roughly along the major axis of the flow. A simple 3D hydrodynamical simulation of the H2 gas in a precessing outflow supports this idea. Observations and model confirm that the molecular Hydrogen gas, traced by the pure rotational transitions, moves at highly supersonic velocities without being dissociated. This suggests either a very efficient mechanism to reform H2 molecules along these shocks or the presence of some other mechanism (e.g. strong magnetic field) that shields the H2 gas.Comment: Accepted for publication in New Journal of Physics (Special Issue article

Expanded Very Large Array Observations of the Nebula Around G79.29+0.46

We have observed the radio nebula surrounding the Galactic luminous blue variable candidate G79.29+0.46 with the Expanded Very Large Array (EVLA) at 6 cm. These new radio observations allow a morphological comparison between the radio emission, which traces the ionized gas component, and the mid-IR emission, a tracer of the dust component. The InfraRed Array Camera (8 μm) and the Multiband Imaging Photometer for Spitzer (24 μm and 70 μm) images have been reprocessed and compared with the EVLA map. We confirm the presence of a second shell at 24 μm and also provide evidence for its detection at 70 μm. The differences between the spatial morphology of the radio and mid-IR maps indicate the existence of two dust populations, the cooler one emitting mostly at longer wavelengths. Analysis of the two dusty, nested shells have provided us with an estimate of the characteristic timescales for shell ejection, providing important constraints for stellar evolutionary models. Finer details of the ionized gas distribution can be appreciated thanks to the improved quality of the new 6 cm image, most notably the highly structured texture of the nebula. Evidence of interaction between the nebula and the surrounding interstellar medium can be seen in the radio map, including brighter features that delineate regions where the shell structure is locally modified. In particular, the brighter filaments in the southwest region appear to frame the shocked southwestern clump reported from CO observations

The X-ray Luminosities of HH Objects

The recent detection of X-ray emission from HH 2 and HH 154 with the Chandra and XMM-Newton satellites (respectively) have opened up an interesting, new observational possibility in the field of Herbig-Haro objects. In order to be able to plan further X-ray observations of other HH objects, it is now of interest to be able to estimate their X-ray luminosities in order to choose which objects to observe. This paper describes a simple, analytic model for predicting the X-ray luminosity of a bow shock from the parameters of the flow (i.e., the size of the bow shock, its velocity, and the pre-shock density). The accuracy of the analytic model is analyzed through a comparison with the predictions obtained from axisymmetric, gasdynamic simulations of the leading working surface of an HH jet. We find that our analytic model reproduces the observed X-ray luminosities of HH 2 and HH 154, and we propose that HH~80/81 is a good candidate for future observations with Chandra.Comment: 10 pages (8 text, 2 figures

Crecimiento postraumático en padres de niños y adolescentes con cáncer.

El cáncer puede provocar reacciones psicológicas negativas. No obstante, la lucha al abordar los problemas oncológicos también puede dar lugar a cambios psicológicos positivos que demuestran la fortaleza del ser humano, siendo una de ellas el crecimiento postraumático (CPT). El objetivo de esta revisión narrativa fue revisar y analizar los artículos, publicados durante los años 2000 a 2018 y disponibles en distintas bases de datos, sobre el CPT en padres y madres de niños y adolescentes con cáncer en el ámbito pediátrico. Se identificaron 20 estudios que incluían 2.422 sujetos, mayoritariamente madres (n=1.788), y que analizaban el CPT en función del parentesco, evolución y tipo de enfermedad del hijo, así como factores predictores del mismo. Tanto padres como madres, son capaces de desarrollar CPT como consecuencia de la experiencia del cáncer de sus hijos, siendo ellas quienes experimentan mayores niveles. En comparación con otras muestras como progenitores de niños con diabetes tipo I o de niños sanos, o pacientes adultos con osteosarcoma, los padres y madres de niños con cáncer refieren mayor CPT. Asimismo, se observan factores que influyen en el desarrollo del CPT, como el contexto cultural, el procesamiento cognitivo, el ajuste a la enfermedad y ciertos rasgos de personalidad. La evidencia científica publicada avala la existencia de CPT en madres y padres de hijos con cáncer. No obstante, sería necesario realizar estudios objetivos, longitudinales, con muestras homogéneas de mayor tamaño, para diseñar intervenciones dirigidas a promocionar ese CPT y no centrarse solo en los aspectos negativos de la enfermedad.post-print213 K