Calendar
CARMENES, the brand-new, Spanish-German, two-channel, ultra-stabilised, high-resolution spectrograph at the 3.5 m Calar Alto telescope, started its science survey on 01 Jan 2016. In one shot, it covers from 0.52 to 1.71 mum with resolution R = 94,600 (lambda less then 0.96) and 80,400 (lambda larger than 0.96 mum). During guaranteed time observations, CARMENES carries out the programme for which the instrument was designed: radial-velocity monitoring of bright, nearby, low-mass dwarfs with spectral types between M0.0 V and M9.5 V. Carmencita is the CARMEN(ES) Cool dwarf Information and daTa Archive, our input catalogue, from which we select the about 300 targets being observed during guaranteed time. Besides that, Carmencita is perhaps the most comprehensive database of bright, nearby M dwarfs ever built, as well as a useful tool for forthcoming exo-planet hunters: ESPRESSO, HPF, IRD, SPIRou, TESS or even PLATO. Carmencita contains dozens of parameters measured by us or compiled from the literature for about 2,200 M dwarfs in the solar neighbourhood brighter than J = 11.5 mag: accurate coordinates, spectral types, photometry from ultraviolet to mid-infrared, parallaxes and spectro-photometric distances, rotational and radial velocities, Halpha pseudo-equivalent widths, X-ray count rates and hardness ratios, close and wide multiplicity data, proper motions, Galactocentric space velocities, metallicities, full references, homogeneously derived astrophysical parameters, and much more. I will briefly describe the instrument CARMENES, the consortium that built it and now operates it, the sample, the status of the science survey, and some ideas for the future.
I will present results from my recent papers based on XMM-Newton observations of young stars in Star Forming Regions near Orion A (Kappa Ori) and Rho Ophiuchi. These observations were aimed at discovering new young stars and infer their ages, their distances and the relationship with the parent cloud. In Kappa Ori, with 40 ks of XMM/EPIC we have derived X-ray fluxes and luminosities of about 120 young stars with and without disks near Kappa Ori (B0 type). X-ray luminosity functions provided a “yardstick” to infer that these stars form a separate cluster centered on Kappa Ori (~250 pc), much closer than ONC (~410 pc) and unrelated to it. In Rho Ophiuchi, with 50+140 ks we have discovered a group of disk-less stars around Rho Oph itself and significantly older (5-10 Myr) than the bulk of YSOs (1 Myr) in the main core of the cloud, L1688. As an unexpected discovery, Rho Oph itself is a periodic emitter of hard X-rays, mimicking a “X-ray lighthouse”, and hinting that either a strong magnetism or an unseen companion are the source of such X-rays.
Space missions are very complex projects with peculiar characteristics such as: strategic importance, extent of international participation, specialized industrial sector, high investment costs, long-term program duration, impossibility of intervening in space for repairs and/or maintenance. These peculiarities strongly influence the realization process since its conception. This talk provides an introduction to methods and tools of project management of a space mission under the guidance of the European Space Agency. The following topics will be covered: General section: – Introduction to management of complex projects; – Key elements for the design of a space mission; – Main phases for the development of a space mission; – The life cycle of ESA programs; – The European Cooperation for Space Standardization (ECSS) documentation for project management and quality control. Phase A study: – Objectives of a phase A; – The main activities of analysis and development; – Preliminary Requirements Review (PRR) documentation.
High resolution spectroscopy, providing constraints on plasma motions and temperatures, is a powerful means to investigate the structure of accretion streams in Classical T Tauri stars (CTTS). In particular the accretion-shock region, where the accreting material is heated to temperatures of a few million degrees, can be probed by X-ray spectroscopy. MHD models predict that this hot post-shock plasma should have an inward bulk motion, with v_post ~ 100 km/s, with respect to the surrounding stellar atmosphere. To verify this prediction we searched for a Doppler shift in the deep Chandra/HETG observation of the CTTS TW Hya, perfectly suited for this task because of the excellent S/N and spectral resolution of the dataset, and because of the ideal target inclination. This test should allow us to constrain definitively the nature of this X-ray emitting plasma component in CTTS, and infer constraints on the accretion stream geometry. We searched for a Doppler shift in the X-ray emission from TW Hya by measuring the position of a selected sample of emission lines. To check the absolute wavelength calibration of the Chandra gratings, and to check whether or not bulk motions with respect to the photosphere are observed in coronal plasma, we also analyzed a sample of Chandra/HETG spectra of non-accreting active stars. We found that the soft part of the X-ray spectrum of TW Hya is significantly red-shifted by ~40 km/s with respect to the known radial velocity of the stellar photosphere. Conversely no X-ray redshift is observed in the X-ray emission of non-accreting active stars. The evidence that the X-ray emitting plasma on TW Hya is moving inward with respect to the stellar surface definitively confirms that it originates in the post-shock region, at the base of the accretion stream, and not in coronal structures. The observed radial velocity indicates that the base of the accretion stream on TW Hya is located at low latitudes on the stellar surface. Moreover the observed velocity of the soft X-ray emitting plasma is very similar to the velocity of the narrow component of the CIV resonance doublet at 1550 A, suggesting that they both originate from the same post-shock regions, that the hypothesis of free-fall regime in the accretion streams holds, and that complex magnetic field geometries, as that of TW Hya, allow low latitude accretion spots.
The Carte du Ciel project is considered the mother of all astrometric enterprises. It was conceived at the end of 19th century and was aimed at photographing the entire sky vault, to produce a catalogue of stars up to magnitude 11 and a chart containing stars up to magnitude 14.. This international endeavour was promoted by Paris Observatory in 1887: 18 observatories from both hemispheres participated in it, more or less successfully. This talk will illustrate how the project was originated and developed, why it remained partially inachieved and what was its impact on the astrometric missions which preceded the current GAIA mission.
Star-Planet Interaction (SPI) is a broad phenomenological term which encompasses a variety of physical effects relevant for the evolution of extra-solar planetary systems, in particular for those hosting giant gas planets in close orbits around their parent star. While theoretical expectations of SPI are abundant, observational signatures are still elusive with current instrumentation and adopted observing strategies. I will review the state of the art on the matter, and possible future developments that may help us for a better characterization of exoplanets and their abitability conditions.
I will talk about two new possibilities to analyse the observational data on non-thermal emission of cosmic rays accelerated in supernova remnants (SNRs). The first one is related to the polarization images of SNRs. In fact, the polarized radio emission has been mapped with great detail in several Galactic supernova remnants, but has not yet been exploited to the extent it deserves. We have developed a method to model maps of the Stokes parameters for shell-like SNRs during their Sedov evolution phase. The second result bases on the time-dependent particle acceleration and relates the temporal evolution of the radio spectral index of SNR in the aftermath of the explosion to the gamma-ray spectrum at later stages. As a test case, we apply our method to describe gamma-rays from IC443; as a proxy of the IC443 parent supernova we consider SN1987A.
It is debated whether the long and intense flares observed on the PMS stars in Orion involve single and very long magnetic channels or much flatter loop arcades. This question is important because the long flaring channels may be so long as to connect the star to the circumstellar disk. In this work a new method solves the question …. (suspence is left on purpose).