Search

Equation of state for Bose-Einstein condensate is evaluated in two cases: non-interacting particles and particles interacting via potential possessing a non-trivial minimum. In astrophysical context, the first case becomes equivalent to cold dark matter, while the second case – to dark energy. A particular cosmological scenario with dark matter injection from quasi-black holes to galactic halo, followed by Bose-Einstein condensation in the intergalactic medium is considered. [ABSTRACT FROM AUTHOR]

When looking at the night sky, dark patches appear evident for the striking contrast with the shining background, populated with stars. These "shadows" were identified as molecular clouds, the coldest and densest phase of the interstellar medium (ISM). In these objects there are the right conditions for the formation of molecules. Up to now, approximately 200 molecular species have been detected, from very simple ones (such as water, or ammonia) to more complicated organic species. Since molecular clouds are also the preferential site where star forms, molecules (through their roto-vibrational transitions) have become a very powerful diagnostic tool to investigate the dynamics of the interstellar medium during the whole star formation process. In my work, I have used ammonia (NH3) data to study the kinematics, density and temperature of the protocluster Barnard 59, a young, low-mass forming region in the Pipe nebula. [ABSTRACT FROM AUTHOR]

In previous papers the authors suggest a clarification of the phenomenon of appearance-disappearance of Kordylewski clouds - accumulation of cosmic dust mass in the vicinity of the triangle libration points of the Earth-Moon system. Under gravi-tational and light perturbation of the Sun the triangle libration points aren’t the points of relative equilibrium. However, there exist the stable periodic motion of the particles, surrounding every of the triangle libration points. Due to this fact we can consider a probabilistic model of the dust clouds formation. These clouds move along the periodical orbits in small vicinity of the point of periodical orbit. To continue this research we suggest a mathematical model to investigate also the electromagnetic influences, arising under consideration of the charged dust particles in the vicinity of the triangle libration points of the Earth-Moon system. In this model we take under consideration the self-unduced force field within the set of charged particles, the probability distribution density evolves according to the Vlasov equation. [ABSTRACT FROM AUTHOR]

It has been known that there is a linearly proportional relationship between the column densities of CH and OH measured toward bright UV-emitting stars, although there are four outliers in this relationship among the total 24 measured targets. By using the Simbad database, we investigate reasonable configurations of diffuse interstellar medium (ISM) which could explain the observed relationship. We first identify the locations of 24 targets on the celestial sphere getting the distances to them and then count the number of molecular clouds, nebulae, and peculiar stars toward the targets which could contribute to the production of OH and CH. We present the results of our search by testing three hypothetical configurations of diffuse ISM which may explain the observed relationship. [ABSTRACT FROM AUTHOR]

Astrophysical observables that are directly linked to nuclear physics inputs provide critical and stringent constraints on nucleosynthetic models. As 26Al was the first specific radioactivity observed in the Galaxy, its origin has fascinated the nuclear astrophysics community for nearly forty years. Despite extensive research, the precise origins of 26Al remain elusive. At present, the sum of all putative stellar contributions generally overestimates the 26Al mass in the interstellar medium. Among the many reactions that influence the yield of 26Al, radiative proton capture on its isomer 26mAl is one of the least constrained reactions by experimental data. To this end, we developed a 26Al isomeric beam and performed proton elastic scattering to search for low-spin states in 27Si. The experimental method and the preliminary results of this on-going study will be presented. [ABSTRACT FROM AUTHOR]

Low-mass population III (PopIII) stars could survive up until the present. They would be found in the halo of Our Galaxy, if they exist. Non-detection of low-mass PopIII stars in our Galaxy suggests that PopIII stars have a top-heavy IMF. On the other hand, some claims that the lack of such stars is as a result of metal enrichment of their surface by accretion of heavy elements from interstellar medium (ISM). We investigate effects of the stellar wind on the metal accretion onto low-mass PopIII stars because accretion of the local ISM onto the Sun is prevented by the solar wind even for neutrals. We find that low-mass PopIII stars traveling across the Galaxy forms the stellar magnetosphere in most of their life. Once the magnetosphere is formed, most of neutral interstellar particles are photoionized before reaching to the stellar surface and are blown away by the wind. This demonstrates that low-mass PopIII stars remain pristine and will be found as metal free stars and that further searches for them are valuable to constrain the IMF of PopIII stars. [ABSTRACT FROM AUTHOR]

Dynamical Dark Matter (DDM) is an alternative framework for dark-matter physics in which the dark sector comprises a vast ensemble of particle species whose Standard-Model decay widths are balanced against their cosmological abundances. In this talk, we study the properties of a hitherto-unexplored class of DDM ensembles in which the ensemble constituents are the "hadronic" resonances associated with the confining phase of a strongly-coupled dark sector. Such ensembles exhibit masses lying along Regge trajectories and Hagedorn-like densities of states that grow exponentially with mass. We investigate the applicable constraints on such dark-"hadronic" DDM ensembles and find that these constraints permit a broad range of mass and confinement scales for these ensembles. We also find that the distribution of the total present-day abundance across the ensemble is highly correlated with the values of these scales. This talk reports on research originally presented in Ref. [1]. [ABSTRACT FROM AUTHOR]

The observation of hydrogen peroxide in the interstellar medium represents a remarkable discovery for the astrochemistry community. The prototypical role that this molecule, arguably the simplest chiral molecule, plays in the evolution of life in biospheres, is related to the chirality change transitions associated with the torsional motions around the O - O and the S - S bonds. In this paper, we present an overview on the state-of-art of possible experiments to demonstrate chiral effects discrimination and computational tools applied to peroxides and persulfides. [ABSTRACT FROM AUTHOR]

We present a summary of the discussion sessions that took place at the CETUP* 2016 Dark Matter Workshop. [ABSTRACT FROM AUTHOR]

The DarkSide-50 direct dark matter detector is a liquid argon time projection chamber (TPC) surrounded by a liquid scintillator neutron veto (LSV) and a water Cerenkov muon veto (WCV). Located under 3800 m.w.e. at the Laboratori Nazionali del Gran Sasso, Italy, it is the only direct dark matter experiment currently operating background free. The atmospheric argon target was replaced with argon from underground sources in April, 2015. The level of 39Ar, a β emitter present in atmospheric argon (AAr), has been shown to have been reduced by a factor of (1.4 ± 0.2) x 10³. The combined spin-independent WIMP exclusion limit of 2.0 x 10-44 cm² (mx = 100 GeV/c²) is currently the best limit on a liquid argon target. [ABSTRACT FROM AUTHOR]

The modeling of X-ray spectra from photoionized astrophysical plasmas has been significantly improved due to recent advancements in the theoretical and numerical frameworks, as well as a consolidated and reliable atomic database of inner-shell transitions for all the relevant ions. We discuss these developments and the current state of X-ray spectral modeling in the context of oxygen cold absorption in the interstellar medium (ISM). Unconventionally, we use high-resolution astrophysical observations to accurately determine line positions, and adjust the theoretical models for a comprehensive interpretation of the observed X-ray spectra. This approach has brought to light standing discrepancies in the neutral oxygen absorption-line positions determined from observations and laboratory measurements. We give an overview of our current efforts to devise a definitive model of oxygen photoabsorption that can help to resolve the existing controversy regarding ISM atomic and molecular fractions. [ABSTRACT FROM AUTHOR]

Fritz Zwicky's hypothesis, according to which the cosmological redshift is due to galactic light losing energy to intergalactic media, without need of Universe expansion, seems to have been recently confirmed by recent mathematical, theoretical and experimental studies via measurements on Earth. But the return to a static universe would imply the inevitable prediction that the universe should collapse due to gravitational attractions among galaxies. In this paper, we present apparently for the first time a cosmological model in which the stability of the universe is achieved under the condition of admitting an equal number of matter and antimatter galaxies (as they are hypothesized in Isodual Theory of Antimatter) at such a large mutual distance for which gravitational interactions are neglectable. [ABSTRACT FROM AUTHOR]

The High Altitude Water Cherenkov (HAWC) Observatory recently began full-scale operations, surveying 2/3 of the entire sky at very high energy (VHE; E > 100 GeV). This new view of the sky offers the opportunity to detect flares from blazars, facilitating studies of the mechanisms powering their central engines and providing an avenue to constrain the properties of particles and fields in intergalactic space. The HAWC Collaboration has implemented an online flare monitor to search for rapid and extreme transient activity from a set of blazars either known or suspected to produce VHE emission. The goal of this project is to issue alerts sufficiently rapidly to form a complete multiwavelength picture of the flare. We describe the current status of the online flare monitor, demonstrating its ability to detect flares via a study of the blazars Markarian 421 and Markarian 501 in offliine data. [ABSTRACT FROM AUTHOR]

By interacting with the cosmic background photons during their propagation through intergalactic space, ultrahigh energy cosmic rays (UHECRs) produce energetic electron/positron pairs and photons which will initiate electromagnetic cascades, contributing to the isotropic gamma-ray background (IGRB). The generated gamma-ray flux level highly depends on the redshift evolution of the UHECR sources. Recently, the Fermi-LAT collaboration reported that 86+16-14 of the total extragalactic gamma-ray flux comes from extragalactic point sources including those unresolved ones. This leaves a limited room for the diffusive gamma ray generated via UHECR propagation, and subsequently constrains their source distribution in the Universe. Normalizing the total cosmic ray energy budget with the observed UHECR flux in the energy band of (1-4)×1018 eV, we calculate the diffuse gamma-ray flux generated through UHECR propagation. We find that in order to not overshoot the new IGRB limit, these sub-ankle UHECRs should be produced mainly by nearby sources, with a possible non-negligible contribution from our Galaxy. The distance for the majority of UHECR sources can be further constrained if a given fraction of the observed IGRB at 820 GeV originates from UHECR. We note that our result should be conservative since there may be various other contributions to the IGRB that is not included here. [ABSTRACT FROM AUTHOR]

Galaxies having a high star-formation rate are predicted to generate high-energy cosmic rays, which produce gamma-rays when they interact with the interstellar medium and radiation fields. In this paper, we search for gamma-ray emission from a group of galaxies within and beyond the Local Group with the Large Area Telescope, the main scientific instrument on the Fermi satellite. We exclude from the search recently detected galaxies (NGC 253, M82, NGC 4945, NGC 1068, NGC 2146, Arp 220). We use seven years of "Pass 8" LAT data from 100 MeV to 100 GeV to constrain the population properties, and eight years of "Pass 8" LAT data for the three galaxies with highest probability of detection (M33, M83, NGC 3690). No new detections are found, and upper limits for the gamma-ray luminosities are calculated. [ABSTRACT FROM AUTHOR]

Runaway stars form bow shocks by sweeping up interstellar matter in their direction of motion. Theoretical models predict a spectrally wide non-thermal component reaching up to gamma-ray energies at a flux level detectable with current instruments. They were motivated by a detection of non-thermal radio emission from the bow shock of BD+43°3654 and a possible detection of non-thermal X-rays from AE Aurigae. A search in the high-energy regime using data from Fermi-LAT resulted in flux upper limits for 27 candidates listed in the first E-BOSS catalogue. We perform the first systematic search for TeV emission from bow shocks of runaway stars. Using all available archival H.E.S.S. I data we search for very-high-energy gamma-ray emission at the positions of bow shock candidates listed in the second E-BOSS catalogue. This catalogue comprises 73 bow shock candidates, 32 of which have been observed with the H.E.S.S. telescopes. None of the observed bow shock candidates shows significant emission in the H.E.S.S. energy range. The resulting upper limits are used to constrain current models for non-thermal emission from these objects. [ABSTRACT FROM AUTHOR]

Interstellar medium clouds in the W28 region are emitting gamma-rays and it is likely that the W28 supernova remnant is responsible, making W28 a prime candidate for the study of cosmic-ray acceleration and diffusion. Understanding the influence of both supernova remnant shocks and cosmic rays on local molecular clouds can help to identify multi-wavelength signatures of probable cosmic-ray sources. To this goal, transitions of OH, SiO, NH3, HCO+ and CS have complemented CO in allowing a characterisation of the chemically rich environment surrounding W28. This remnant has been an ideal test-bed for techniques that will complement arcminute-scale studies of cosmic-ray source candidates with future GeV-PeV gamma-ray observations. [ABSTRACT FROM AUTHOR]

Pulsar wind Nebulae (PWNe) represent the largest population of TeV sources detected by H.E.S.S. Here, we present a ISM study combining 7mm Mopra observations with Nanten CO(1-0) and SGPS Hi data to understand the ISM environment towards HESS J1809-193, HESS J1026-582 and HESS J1826-130, as well as the morphology of the TeV source gamma-ray emission. Combining the TeV emission with several extended dense regions will then be useful to quantify the distinguish the contribution from PWNe and SNRs towards various HESS TeV sources. [ABSTRACT FROM AUTHOR]

High-velocity clouds (HVCs) are HI clouds with velocities of more than 100 km s-1. These clouds do not partake of the differential Galactic rotation; a significant fraction of them are falling down towards the Galactic disk. The typical mass of these clouds is ~ 104 M☉, so in a collision with the disk energies of the order of ~ 1051 erg can be released into the interstellar medium. Such collisions should produce strong shocks propagating through both the cloud and the disk. Under adequate conditions, these shocks can accelerate particles up to relativistic energies by Fermi mechanism. In this work, we study the hydrodynamical interactions and the relevant radiative processes (thermal and non-thermal) associated with HVC-disk collisions. We find that a shock propagating through a typical cloud should give rise to significant non-thermal radio emission, whereas the protons accelerated there diffuse and might emit elsewhere. A shock propagating through the disk, on the other hand, produces extended gamma-ray emission and injects protons with energies from 10 GeV to ~ 1 TeV. Taking into account the injected mass rate of HI in our Galaxy by cloud bombardement, we found that ~ 10 % of the Galactic cosmic ray power could be generated by these cloud-disk collisional events. [ABSTRACT FROM AUTHOR]

The diffuse γ-ray emission produced by hadronic interaction of cosmic rays (CR) with the interstellar medium (ISM) during their propagation through the Galaxy, reveals important information on the diffusion properties of the ISM as well as on the global distribution of CR sources. In this work we estimate the contribution of γ-ray emission due to the CR self-confined near their acceleration sites. In fact, when CR leave their parent source, they self-generate magnetic turbulence through streaming instability. Such turbulence, in turn, enhances the scattering rate of CRs, increasing their residence time in the region. The streaming instability can be effective within a distance of the order of the coherence scale, Lc, of the background magnetic field from the source, where the density of CRs produced by the source is expected to be larger than the average Galactic value. Nevertheless, the effectiveness strongly dependents on the density of neutral hydrogen, because the ion-neutral friction can suppress the wave amplification. A direct consequence of the self-confinement of CRs is the formation of an extend halo of γ-ray emission of size ~ Lc around each source. The emission from a single halo is too faint to be detected but the sum of these halos over the whole CR source population can be a non negligible contribution to the diffuse gamma-ray emissivity from the Galactic disc. Therefore, we want to compare the predicted emission from the total halo's population with the diffuse Galactic emission measured by the Fermi-LAT telescope. To do this calculation, we assume that CR sources are Supernova Remnants (SNRs) exploding either in a fully ionized or in a partially ionized ISM. While in the former case the halos emission almost saturate the observed Galactic emission, in the latter, due to the ion-neutral friction, the gamma-ray emission is strongly reduced, being non negligible only for energies of γ-rays Eγ ~ 100 GeV. [ABSTRACT FROM AUTHOR]

TeV gamma-ray astronomy and the interstellar medium (ISM) are intimately linked via fundamental particle physics processes. Over 100 TeV gamma-ray sources in our galaxy are now known, although a large fraction of them remain unidentified either in terms of their countpart accelerator and/or the type of particles responsible for the emission. With the forthcoming Cherenkov Telescope Array (CTA) offering arc-minute angular gamma-ray resolution, similar resolution ISM surveys will be needed to help understand the variety of particle astrophysics issues the CTA will uncover in its Galactic plane and other survey science. In this review I will look at the status of the unidentified TeV gamma-ray sources, the key particle physics issues, the forthcoming ISM surveys, and then see how these will link in to CTA. [ABSTRACT FROM AUTHOR]

Although the concept of a potential curve is one of the important outgrowths of the Born-Oppenheimer (BO) approximation, we propose a method to obtain an analytical potential curve from the Non-Born-Oppenheimer (Non-BO) wave functions. The present proceeding reviews this method originally published in J. Chem. Phys. 139, 074105 (2013). A numerical examination was performed with hydrogen molecular ion, where the free complement method was employed to solve the Non-BO Schrödinger equation very accurately. Whereas an ordinary potential curve on the BO approximation is obtained as a numeric curve evaluated at many fixed nuclear coordinates and curve fitting is always required, the present method can describe the potential curve as an analytical continuous function. It indicates that a single Non-BO calculation principally draws the whole potential curve at any nuclear coordinates. [ABSTRACT FROM AUTHOR]

After a brief review of the cosmological lithium problem, we report a few recent attempts to find theoretical solutions by our group at Texas A&M University (Commerce & College Station). We will discuss our studies on the theoretical description of electron screening, the possible existence of parallel universes of dark matter, and the use of non-extensive statistics during the Big Bang nucleosynthesis epoch. Last but not least, we discuss possible solutions within nuclear physics realm. The impact of recent measurements of relevant nuclear reaction cross sections for the Big Bang nucleosynthesis based on indirect methods is also assessed. Although our attempts may not able to explain the observed discrepancies between theory and observations, they suggest theoretical developments that can be useful also for stellar nucleosynthesis. [ABSTRACT FROM AUTHOR]

Fullerenes and hydrogenated fullerenes are found in circumstellar and interstellar environments. But the determination structures for the detected bands in the interstellar and circumstellar space are not completely understood so far. For that purpose, the aim of this article is to provide all possible infrared spectra for C20 and C60 fullerenes and their hydrogenated fullerenes. Density Functional theory (DFT) is applied using B3LYP exchange-functional with basis set 6-31G(d, p). The Fourier transform infrared spectroscopy (FT-IR) is found to be capable of distinguishing between fullerenes, mono hydrogenated fullerenes and fully hydrogenated fullerenes. In addition, deposition of one hydrogen atom outside the fully hydrogenated fullerenes is found to be distinguished by forming H2 molecule at peak around 4440 cm-1. However, deposition of one hydrogen atom inside the fully hydrogenated fullerenes cannot be distinguished. The obtained spectral structures are analyzed and are compared with available experimental results. [ABSTRACT FROM AUTHOR]

The precise interstellar neutral (ISN) flow direction is important because of its strong leverage on the plane subtended by the ISN and magnetic field vectors, which controls the heliospheric shape and interaction with the interstellar medium. IBEX measurements provide a very precise relation between ISN flow longitude and speed via the hyperbolic trajectory equation, forming a 4-dimensional tube in the ISN parameter space, with substantially larger uncertainty along this tube and thus for the longitude alone. As demonstrated before, the interstellar pickup ion (PUI) cut-off speed is a function of the ratio of the radial ISN flow component and the solar wind speed at the observer location. The former is largest precisely upwind and decreases symmetrically with the angle from the upwind direction. Using this functional dependence and the observed solar wind speed, the PUI cut-off can be constructed solely as a function of the ISN flow longitude. From ACE SWICS and STEREO PLASTIC, data sets that span 18+ years are available. We will show, in particular, that by selecting observations for local interplanetary magnetic fields perpendicular to the solar wind and transforming the observed distributions into the solar wind frame, a comparison with data can be devised that is much less sensitive to PUI production and transport effects than methods that rely on pickup ion fluxes. [ABSTRACT FROM AUTHOR]

The outer boundary conditions of the heliosphere are set by the circumheliospheric interstellar medium, which is part of the Local Interstellar Cloud (LIC). In particular the ram pressure, ionization and magnetic field strength are important for determining the size and shape of the heliosphere. The in situ as well as line of sight data indicate that the LIC is a warm, partially ionized cloud. We discuss the observational evidence on the nature of the LIC and theoretical models that explain its temperature and ionization. [ABSTRACT FROM AUTHOR]

Since launch in Oct. 2008, IBEX, with its two energetic neutral atom (ENA) cameras, has provided humankind with the first-ever global images of the complex boundary separating the heliosphere from the local interstellar medium (LISM). IBEX's energy-resolved all-sky maps, collected every six months, are yielding remarkable new insights into the heliospheres structure as it is shaped by the combined forces of the local interstellar flow, the local interstellar magnetic field (LISMF), and the evolving solar wind. IBEX has also acquired the first images of ENAs backscattered from the surface of the moon as well as global images of the magnetospheric response to solar wind disturbances. IBEX thus addresses all three Heliophysics science objectives set forth in the 2014 Science Plan for NASAs Science Mission Directorate (SMD) as well as the goals in the recent Solar and Space Physics Decadal Survey (NRC 2012). In addition, with the information it provides on the properties of the LISM and the LISMF, IBEX represents a unique bridge between heliophysics and astrophysics, and fills in critical knowledge for understanding the habitability of exoplanetary systems and the future habitability of Earth and the solar system. Because of the few-year time lag due to solar wind and ENA transport, IBEX observed the solar wind/LISM interaction characteristic of declining phase/solar minimum conditions. In the continuing mission, IBEX captures the response of the interstellar boundaries to the changing structure of the solar wind in its transition toward the "mini" solar maximum and possibly the decline into the next solar minimum. The continuing IBEX mission affords never-to-be-repeated opportunities to coordinate global imaging of the heliospheric boundary with in-situ measurements by the Voyagers as they pass beyond the heliopause and start to directly sample the LISM. [ABSTRACT FROM AUTHOR]

The Voyager spacecraft are making the first direct plasma measurements of the heliosheath and interstellar medium. This paper discusses the differences in the heliosheath observations of Voyager 1 (V1) and Voyager 2 (V2), the V1 heliopause crossing, and observations of transient structures in the local interstellar medium (LISM). The heliosheath velocities at V1 are smaller than expected throughout the heliosheath and are zero in the stagnation region, which persists for 8 AU before the heliopause crossing. The V2 flow profile is very different from that at V1; the average speed stays constant at 145 km/s but the flow has turned over 60? from radial. The heliopause crossing region has numerous structures in cosmic rays, termination shock particles, and magnetic field so that the exact heliopause crossing point is still controversial. Solar transients drive shocks which propagate through the LISM, generate anisotropies and intensity changes in the galactic cosmic rays (GCRs) and excite plasma and radio waves. [ABSTRACT FROM AUTHOR]

Interstellar PickUp Ions (PUIs) are created from neutrals coming from the interstellar medium that get ionized inside the heliosphere. Once ionized, the freshly created ions are injected into the magnetized solar wind plasma with a highly anisotropic torus-shaped Velocity Distribution Function (VDF). It has been commonly assumed that wave-particle interactions rapidly destroy this torus by isotropizing the distribution in one hemisphere of velocity space. However, recent observations of a He+ torus distribution using PLASTIC on STEREO showed that the assumption of a rapid isotropization is oversimplified. The aim of this work is to complement these studies. Using He+ data from the Charge Time-Of-Flight (CTOF) sensor of the Charge, ELement, and Isotope Analysis System (CELIAS) on-board the SOlar and Heliospheric Observatory (SOHO) and magnetic field data from the Magnetic Field Investigation (MFI) magnetometer of the WIND spacecraft, we derive the projected 1-D VDF of He+ for different magnetic field configurations. Depending on the magnetic field direction, the initial torus VDF lies inside CTOF's aperture or not. By comparing the VDFs derived under different magnetic field directions with each other we reveal an anisotropic signature of the He+ VDF. [ABSTRACT FROM AUTHOR]

Despite the extreme conditions of temperature (down to 10K) and density (down to 100 molecules/cm3), the giant molecular clouds and the circumstellar envelopes present a rich and complex chemistry. To date, more than 180 molecules have been detected in the InterStellar Medium (ISM) with a large abundance of nitriles (RC=N). In addition, several anions have been recently observed in this medium: C4H, C6H, C8H, CN, C3N and C5N. These last species should play a key role in the molecular growth towards complexity. To explore this hypothesis, their reactivity must be studied in the laboratory. The FALP-MS and the CRESU experimental apparatuses of the Rennes University are able to measure absolute rate coefficient of various chemical reactions, including the ion - molecule reactions, in gas phase at low temperature (from 300K for the FALP-MS down to 15K for the CRESU). Therefore, these experimental tools are particularly adapted to the kinetic studies of reactions potentially involved in the Interstellar Medium. One of the difficulties encountered in experiments with anions is their generation. We describe here the formation of the CN and C3N anions by dissociative electron attachment on the molecular precursors BrCN and BrC3N. [ABSTRACT FROM AUTHOR]

Accurate and detailed three-dimensional (3D) maps of Galactic interstellar medium (ISM) are still lacking. One way to obtain such 3D descriptions is to record a large set of individual absorption or reddening measurements toward target stars located at various known distances and directions. The inversion of these measurements using a tomographic method can produce spatial distribution of the ISM. Until recently absorption data were very limited and distances to the target stars are still uncertain, but the situation will greatly improve thanks to current and future massive stellar surveys from ground, and to Gaia mission. To prepare absorption data for inversion from a huge number of stellar spectra, automated tools are needed. We have developed various spectral analysis tools adapted to different type of spectra, early- or late- type star. We also have used diffuse interstellar bands (DIBs) to trace IS structures and kinematics. Although we do not know yet their carriers, they can be a promising tool to trace distant interstellar clouds or Galactic arms. We present some examples of the interstellar fitting and show the potentiality of DIBs in tracing the ISM. We will also briefly show and comment the latest 3D map of the local ISM which reveal nearby cloud complexes and cavities. [ABSTRACT FROM AUTHOR]

We present here a short overview of the main classes of methods used to generate diamond nanostructures. The described methodologies, namely the CVD techniques, the explosive reactions, the laser-induced processes and the plasma treatments, offer the feasibility to produce nanosized diamonds in forms of powders or films, to modulate size, shape and structure of individual nanograins or of nanodiamond aggregates, to build complex architectures. A proper design and a subsequent controlled production of diamond structures at the nanoscale are strict requirements for the transition from fundamental material research to real-world applications. [ABSTRACT FROM AUTHOR]

Violent eruptions, and consequently major mass loss, are a common feature of the so-called Luminous Blue Variable (LBV) stars. During major eruptive episodes LBVs mimic the behavior of real type IIn supernovae (SNe), showing comparable radiated energy and similar spectroscopic properties. For this reason these events are frequently labelled as SN impostors. Type IIn SN spectra are characterized by the presence of prominent narrow Balmer lines in emission. In most cases, SNe IIn arise from massive stars (M>8⊙) exploding in a dense H-rich circumstellar medium (CSM), produced by progenitor's mass loss prior to the SN explosion. Although the mechanisms triggering these eruptions are still unknown, recently we had direct proofs of the connection between very massive stars, their eruptions and ejecta-CSM interacting SNe. SNe 2006jc, 2010mc, 2011ht and the controversial SN 2009ip are famous cases in which we observed the explosion of the star months to years after major outbursts. In this context, the case of a recent transient event, LSQ13zm, is extremely interesting since we observed an outburst just ~3 weeks before the terminal SN explosion. All of this may suggest that SN impostors occasionally herald true SN explosions. Nonetheless, there are several cases where major eruptions are followed by a quiescent phase in the LBV life. The impostor SN 2007sv is one of these cases, since it showed a single outburst event. Its photometric (a relatively faint absolute magnitude at the maximum) and spectroscopic properties (low velocity and temperature of the ejecta, and the absence of the typical elements produced in the explosive nucleosynthesis) strongly suggest that SN 2007sv was the giant eruption of an LBV, which has then returned in a quiescent stage. [ABSTRACT FROM AUTHOR]

The discovery of H3+ in the diffuse interstellar medium has dramatically changed our view of the cosmic-ray ionization rate in diffuse molecular clouds. However, another surprise has been that the ortho:para ratio of H3+ in these clouds is inconsistent with the temperature derived from the excitation of H2, the dominant species in these clouds. In an effort to understand this discrepancy, we have embarked on an experimental program to measure the nuclear spin dependence of the dissociative electron recombination rate of H+ using the CRYRING and TSR ion storage rings. We have also performed the first measurements of the reaction H3+ + H2 → H2 + H3+ below room temperature. This reaction is likely the most common bimolecular reaction in the universe, and plays an important role in interconverting ortho- and para-H3+. Finally, we have constructed a steady-state chemical model for diffuse clouds, which takes into account the spindependence of the formation of H3+, its electron recombination, and its reaction with H2. We find that the ortho:para ratio of H3+ in diffuse clouds is likely governed by a competition between dissociative recombination and thermalization by reactive collisions. [ABSTRACT FROM AUTHOR]

Based on our new calculations of its structure, we discuss the possibility for the H3- ion to be formed and observed in cold and dense interstellar medium in an environment with a large fraction of ionized molecular hydrogen. The detection the H- ion would be a probe for the presence of H- in the interstellar medium. [ABSTRACT FROM AUTHOR]

The detection of negatively charged molecules in the interstellar and circumstellar medium in the past four years has been one of the most impacting surprises in the area of molecular astrophysics. It has motivated the interest of astronomers, physicists, and chemists on the study of the spectroscopy, chemical kinetics, and prevalence of molecular anions in the different astronomical regions. Up to six different molecular anions have been discovered in space to date, the last one being the small ion CN-, which has been observed in the envelope of the carbon star IRC +10216 and which contrary to the other larger anions is not formed by electron attachment to CN, but through reactions of large carbon anions with nitrogen atoms. Here we briefly review the current status of our knowledge of the chemistry of molecular anions in space, with particular emphasis on the circumstellar source IRC +10216, which to date is the astronomical source harboring the largest variety of anions. [ABSTRACT FROM AUTHOR]

Hydrides are key ingredients of interstellar chemistry since they are the initial products of chemical networks that lead to the formation of more complex molecules. The fundamental rotational transitions of light hydrides fall into the submillimeter wavelength range. Using the APEX telescope, we observed the long sought hydrides SH+ and OH+ in absorption against the strong continuum source Sagittarius B2(M). Both, absorption from Galactic center gas as well as from diffuse clouds in intervening spiral arms over a large velocity range is observed. The detected absorption of a continuous velocity range on the line of sight shows these hydrides to be an abundant component of diffuse clouds. In addition, we used the strongest submillimeter dust continuum sources in the inner Galaxy to serve as background candles for a systematic census of these hydrides in diffuse clouds and massive star forming regions of our Galaxy and initial results of this survey are presented. [ABSTRACT FROM AUTHOR]

Frequencies of pure rotational transitions of molecular anions or cations which are important in the studies of interstellar chemistry are measured precisely by using an Evenson-type tunable far-infrared spectrometer (TuFIR) based on the difference frequency generation of two CO2 lasers. The specs (accuracy, sensitivity) of the spectrometer is introduced together with the examples of the studies of cations (HeH+, H2D+, etc), and anions (OH-, OD-). Also, recent improvement of the spectrometer using extended negative glow discharge cell is shown with preliminary studies of N2H+ [ABSTRACT FROM AUTHOR]

Protonated methane (CH5+) is thought to be a highly abundant molecular ion in interstellar medium, as well as a potentially bright μwave-mm wave emitter that could serve as a tracer for methane. This paper describes progress and first successful efforts to obtain a high resolution, supersonically cooled spectrum of CH5+ in the 2900-3100 cm-1 region, formed in a slit supersonic discharge at low jet temperatures and with sub-Doppler resolution. Short term precision in frequency measurement (< 5 MHz on an hour time scale) is obtained from a thermally controlled optical transfer cavity servoloop locked onto a frequency stabilized HeNe laser. Long term precision (< 20 MHz day-to-day) due to pressure, temperature and humidity dependent index of refraction effects in the optical transfer cavity is also present and discussed. [ABSTRACT FROM AUTHOR]

Molecular ions play a central role in the gas-phase chemistry of the interstellar medium; they also provide information on the physical conditions in astronomical sources (e.g., fractional ionization), and in some cases can be used to infer the abundance of nonpolar molecules such as N2 and CO2 which can not be observed in the radio band. During the past four years, the rotational spectra of six carbon-chain anions (C2H-, C4H-, C6H-, C8H-, CN-, C3N-), NCO- and seven protonated species (HSCO+, HSCS+, cis- and trans-HOSO+, H2NCO+, HNCOH+, and HNNO+) have been detected in our laboratory. On the basis of dedicated astronomical searches, all of the carbon-chain anions except C2H- have now been identified in space. In addition to highlighting recent work on carbon-chain anions and protonated HSO+, efforts to better understand the distribution of anions in space using C6H- as a tracer for negative charge are described. [ABSTRACT FROM AUTHOR]

Prior to the launch of Herschel, HCl was the only chlorine-containing molecule detected in the interstellar medium (ISM). However, chemical models have identified chloronium, H2Cl+, as a relatively abundant species that is potentially detectable. H2Cl+ was predicted to be most abundant in the environments where the ultraviolet radiation is strong: in diffuse clouds, or near the surfaces of dense clouds illuminated by nearby O and B stars. The HIFI instrument on Herschel provided the first detection of H2Cl+ in the ISM. The 212-101 lines of ortho-H235Cl+ and ortho-H237Cl+ were detected in absorption toward NGC 6334I, and the 111-000 transition of para-H2 35Cl+ was detected in absorption toward NGC 6334I and Sgr B2(S). The derived HCl/H2Cl+ column density ratios, శ1--10, are within the range predicted by models of diffuse and dense Photon Dominated Regions (PDRs). However, the observed H2Cl+ column densities, in excess of 1013 cm-2, are significantly higher than the model predictions. These observations demonstrate the outstanding spectroscopic capabilities of HIFI for detecting new interstellar molecules and providing key constraints for astrochemical models. [ABSTRACT FROM AUTHOR]

The astrochemistry of the HnO+ (n=1..3) ions is important as the main gas-phase formation route for water, and as tracer of the interstellar ionization rate by cosmic rays and other processes. While interstellar H3O+ has been known since the early 1990's, interstellar OH+ and H2O+ have only recently been detected using the Herschel space observatory and also from the ground. This paper reviews detections of HnO+ toward external galaxies and compares with ground-based work. The similarities and differences of the HnO+ chemistry within the Galaxy and beyond are discussed. [ABSTRACT FROM AUTHOR]

Laboratory identification of two basic and important interstellar molecular ions is presented. The J = 1 - 0 rotational transition of 12CH+ together with those of 13CH+ and 12CD+ was observed in the laboratory. The newly obtained frequencies were found to be different from those reported previously. Various experimental evidences firmly support the new measurements. In addition, the Zeeman effect and the spin-rotation hyperfine interaction enforce the laboratory identification with no ambiguity. Rotational lines of CH2D+ were observed in the submillimeter-wave region. This laboratory observation is consistent with a recent tentative identification of CH2D+ toward Ori IRc2. [ABSTRACT FROM AUTHOR]

Prior to the launch of Herschel, HCl was the only chlorine-containing molecule detected in the interstellar medium (ISM). However, chemical models have identified chloronium, H2Cl+, as a relatively abundant species that is potentially detectable. H2Cl+ was predicted to be most abundant in the environments where the ultraviolet radiation is strong: in diffuse clouds, or near the surfaces of dense clouds illuminated by nearby O and B stars. The HIFI instrument on Herschel provided the first detection of H2Cl+ in the ISM. The 212-101 lines of ortho-H235Cl+ and ortho-H237Cl+ were detected in absorption toward NGC 6334I, and the 111-000 transition of para-H2 35Cl+ was detected in absorption toward NGC 6334I and Sgr B2(S). The derived HCl/H2Cl+ column density ratios, శ1--10, are within the range predicted by models of diffuse and dense Photon Dominated Regions (PDRs). However, the observed H2Cl+ column densities, in excess of 1013 cm-2, are significantly higher than the model predictions. These observations demonstrate the outstanding spectroscopic capabilities of HIFI for detecting new interstellar molecules and providing key constraints for astrochemical models. [ABSTRACT FROM AUTHOR]

Laboratory identification of two basic and important interstellar molecular ions is presented. The J = 1 - 0 rotational transition of 12CH+ together with those of 13CH+ and 12CD+ was observed in the laboratory. The newly obtained frequencies were found to be different from those reported previously. Various experimental evidences firmly support the new measurements. In addition, the Zeeman effect and the spin-rotation hyperfine interaction enforce the laboratory identification with no ambiguity. Rotational lines of CH2D+ were observed in the submillimeter-wave region. This laboratory observation is consistent with a recent tentative identification of CH2D+ toward Ori IRc2. [ABSTRACT FROM AUTHOR]

The rates for the 17O(p,a)14N, 17O(p,?)18F and 18O(p,a)15N reactions deduced trough the Trojan Horse Method (THM) have been introduced into a state-of-the-art asymptotic giant branch (AGB) models for proton-capture nucleosynthesis and cool bottom process. The predicted abundances have been compared with isotopic compositions provided by geochemical analysis of presolar grains. As a result, an improved agreement is found between the models and the isotopic mix of oxide grains of AGB origins, whose composition is the signature of low-temperature proton-capture nucleosynthesis. [ABSTRACT FROM AUTHOR]

We analyzed X-ray light curves of a unique black hole binary in our Galaxy, GRS 1915+105. We used Rossi X-ray Timing Explorer (RXTE) data between 2007-2008 observations, during which GRS 1915+105 was mostly in its low intensity state. We obtained a total of 93 data with various variability patterns. In this work, we only focused on those data (45 observation data) with low intensity (less than 10,000 counts/s) and without complex variability patterns, known as State A. Previous studies on state A were limited to those occur sporadically due to the lack of observation data since, most of the time, GRS 1915+105 stays at high intensity state. We aimed to study the behavior of long term interval of state A in GRS 1915+105. Similar to the previous studies, we used color-color diagram for our analysis after correcting for the background. We also considered the absorption effect of the interstellar medium which is dominant below 10 keV. In general, the obtained results are in good agreement with the previous studies. However, there are some data that show different behavior which need further studies. [ABSTRACT FROM AUTHOR]

Light extra U(1) gauge bosons, so called hidden photons, which reside in a hidden sector have attracted much attention since they are a well motivated feature of many scenarios beyond the Standard Model and furthermore could mediate the interaction with hidden sector dark matter. We review limits on hidden photons from past electron beam dump experiments including two new limits from such experiments at KEK and Orsay. In addition, we study the possibility of having dark matter in the hidden sector. A simple toy model and different supersymmetric realisations are shown to provide viable dark matter candidates in the hidden sector that are in agreement with recent direct detection limits. [ABSTRACT FROM AUTHOR]