Calendar

The first characteristic measured for Cepheids is their periods. The next step is to determine their pulsation mode. We have made month long observations with the MOST satellite of a fundamental mode Cepheid (RT Aur) and an overtone Cepheid (SZ Tau). The quantity and quality of the satellite data have shown that the Fourier parameters of the overtone are far more variable than those of the fundamental. A series of studies have been made of the binary properties of Cepheids, providing insight into star formation and dynamical evolution. A survey of 70 Cepheids was made with HST WFC3 to identify possible resolved companions. This was followed up with XMM-Newton observations to determine which possible companions are young X-ray active stars, and hence physical companions of Cepheids. This provides information about the frequency, separations, and mass ratios. Finally, the measured masses of Cepheids will be summarized, and new developments discussed.

Evidence for some super-hot plasma (> 4 MK) has been found in the core of active region loops. This is a signature of impulsive heating (nano-flaring). We study the EUV light curves in one or a few pixels with a model of multi-stranded coronal loop. Each strand is pulse-heated. In the hypothesis of an energy distribution of the heat pulses, we first generate a grid of strand models with different heating rates, and then we combine them randomly to generate simulated light curves similar to the observed ones. We make 10000 realisations for each set of model parameters (the power law index of the energy distribution, the duration of the heat pulse, the number of strands) and compare them to the observed light curves to find the best one by means of an artificial intelligence system (Probabilistic Neural Network, PNN). Cross-Correlation is used as a cross-check. We find that a shallow (but not flat) distribution of short-duration pulses in a relatively high number of strands (1000) best describes the observed data. A space-resolved loop model with these parameters predicts different fluctuations of the emission from the bottom to the top of the loop: we compare with observation.

We are using the GMOS integral field unit on the Gemini telescopes to investigate the kinematics of the circum-nuclear ionized gas in a sample of nearby AGNs spanning a wide range of nuclear hard X-ray luminosity (a proxy for the SBH accretion rate). The study aims at investigating the mechanisms channeling gas (the supermassive black hole fuel) from the inner kiloparsec down to few tens of parsecs from the supermassive black hole. The galaxy NGC 1386 turned out to be one of the most interesting sources: we found that the dominant kinematic components can be explained as a combination of rotation in the large-scale galactic disk and compact outflows along the axis of the AGN “radiation cone”. However, there is also compelling evidence for an equatorial outflow. A new clue to the physical processes operating in AGNs?

In our Galaxy, star formation occurs in a variety of environments, with a large fraction of stars formed in clusters hosting massive stars. OB stars have an important feedback on the evolution of protoplanetary disks orbiting around nearby young stars and likely on the process of planet formation occurring in them. The nearby massive association Cygnus OB2 is an outstanding laboratory to study this feedback. It is the closest massive association to our Sun, and hosts hundreds of massive stars and thousands of low mass members, both with and without disks. We have analyzed the spatial variation of the disk fraction (i.e. the fraction of cluster members bearing a disk) in Cygnus OB2 and and studied its correlation with the local values of Far and Extreme ultraviolet radiation fields and the local stellar surface density. We found evidence that disks are more rapidly dissipated in the regions of the association characterized by intense local UV field and large stellar density. In particular, the FUV radiation dominates disks dissipation timescales in the proximity (i.e. within 0.5 pc) of the O stars. In the rest of the association, EUV photons potentially induce a significant mass loss from the irradiated disks across the entire association, but the efficiency of this process is reduced at increasing distances from the massive stars due to absorption by the intervening intracluster material. Comparing our results to what has been found in other young clusters with different massive populations, it is possible to conclude that massive associations like Cygnus OB2 are potentially hostile to protoplanetary disks, but that the environments where disks can safely evolve in planetary systems are likely quite common in our Galaxy.

The race towards the discovery and characterization of terrestrial extrasolar planets, possibly in the habitable zone of their host stars, that recent statistical analyses revealed to have high occurrence rates, represents a scientific adventure rich of great expectations, but also of great challenges. I will address the subject starting from my experience in planet hunting as a collaborator of the Italian ground-based surveys GAPS and APACHE, that aim for a similar goal in complementary ways: through the analysis of the stellar radial velocity variations the first, with the photometric transit method the second. In particular, I will explore the limits imposed by signals of stellar origin to the detection and mass determination of another Earth in precise radial velocity measurements, discussing some proposed strategies to mitigate the impact of stellar noise. Moreover, I will focus the discussion on M dwarfs, which represent a treasure trove for the search of Earth-like planets, but demand particular attention both for the detection and characterization of small planets.

Colliding neutron stars (NSs) are strong sources of gravitational radiation, and one of the most promising candidates for direct detection by advanced LIGO. Following the spectacular observations of gravitational waves from GW150914 – produced by the collision of two black holes – we can now expect that the direct detection of NS collisions is just around the corner. Growing observational evidence shows that NS collisions also produce bright electromagnetic signals: gamma-ray bursts, and macronovae. The former are brief flashes of gamma-ray radiation, the latter are short-lived infrared transients powered by the radioactive decay of heavy nuclei. The simultaneous detection of both electromagnetic and gravitational radiation arising from NS collisions would be a revolutionary observation. This exciting prospect makes these systems prime targets in the era of multi-messenger astronomy. In this talk, I present ongoing observational efforts to characterize the electromagnetic signatures of NS collisions, and outline future initiatives aimed at exploring the gravitational wave sky.

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.