We present the current standing of an investigation into the structure of the Milky Way. We use smoothed particle hydrodynamics (SPH) to simulate the ISM gas in the Milky Way under the effect of a number of different gravitational potentials representing the spiral arms and nuclear bars, both fixed and time-dependent. The gas is subject to ISM cooling and chemistry, enabling us to track the CO and HI density. We use a 3D grid-based radiative transfer code to simulate the emission from the SPH output, allowing for the construction of synthetic longitude-velocity maps as viewed from the Earth. By comparing these maps with the observed emission in CO and HI from the Milky Way ([Dame et al. 2001, Kalberla et al. 2005]), we can infer the arm/bar geometry that provides a best fit to our Galaxy. By doing so we aim to answer key questions concerning the morphology of the Milky Way such as the number of the spiral arms, the pattern speeds of the bar(s) and arms, the pitch angle of the arms and shape of the bar(s).

In the 1990s the hydrogen molecule, by far the most abundant molecular species in the interstellar medium, has been proposed as a possible carrier of the diffuse interstellar bands. While some remarkable coincidences were found in the rich spectrum of inter-Rydberg transitions of this molecule with DIB-features, both in frequency position as in linewidth, some open issues remained on a required non-linear optical pumping scheme that should explain the population of certain intermediate levels and act as a selection mechanism. Recently a similar scheme has been proposed relating the occurrence of the UV-bump (the ubiquitous 2170 Å extinction feature) to the spectrum of H2, therewith reviving the H2 hypothesis.

We present a new method devoted to chemical tagging for Galactic Archeology. In the context of the Gaia-ESO Survey (GES) and the Gaia Data Processing and Analysis Consortium (DPAC), we aim at preparing the Gaia-Radial Velocity Spectrograph analysis, which will provide ~ 2×106 spectra covering the IR CaII triplet domain (R ~ 11 500), with sufficient SNR to perform chemical tagging. Our method will be integrated in the Gaia DPAC Apsis pipeline (CU8, Astrophysical Parameters) and we test it with GES GIRAFFE spectra (MEDUSA mode, HR10 & HR21) deriving abundances of MgI in 168 stars.

Carbon and oxygen abundances in F and G main-sequence stars ranging in metallicity from [Fe/H] = −1.6 to +0.5 are determined from a non-LTE analysis of C i and O i atomic lines in high-resolution spectra. Both C and O are good tracers of stellar populations; distinct trends of [C/Fe] and [O/Fe] as a function of [Fe/H] are found for high- and low-alpha halo stars and for thick- and thin-disk stars. These trends and that of [C/O] provide new information on the nucleosynthesis sites of carbon and the time-scale for the chemical enrichment of the various Galactic components.

The advent of Milky Way high-resolution spectroscopic surveys has brought our attention to the importance of precise chemical abundance measurements to disentangle the stellar population puzzle of the Galaxy. Moreover, automated stellar parameters are the bedrock of Galactic spectroscopic surveys science. They allow a rapid and homogeneous processing of extensive data sets, necessary for an efficient scientific return. In this review, I discuss the different parametrization techniques, focusing on the automated determination of individual element abundances. Each of them has its optimal application conditions that mainly depend on the computation time constraints, the spectral resolution, the wavelength domain, the data signal-to-noise ratio and parameter degeneracy problems. The main algorithms in the literature are also reviewed.

We present and discuss recent results from observations of bright Type Ia supernovae as probes of physical and chemical condtions of extra-galactic interstellar clouds. To illustrate the case we present new results obtained for SN 2009ig.

We present chromospheric activities of late-type stars based on stellar spectrum survey of LAMOST (also called GuoShouJing telescope) in 2010-2013. Using the equivalent widths of the Hα line (larger than 1 Å), we have found 6391 active stars from 99741 M stars.

We are carrying out near-infrared spectroscopy of Cepheids in the Galactic nuclear disk. The H-band spectra taken with SUBARU/IRCS indicate that their kinematics are consistent with the rotation of the nuclear disk.

The Chinese Astronomical Data Center (CAsDC) is a member of World Data System, hosted at National Astronomical Observatories, Chinese Academy of Sciences(NAOC). The CAsDC keeps close collaboration with IVOA, WDS and CODATA. The whole set of LAMOST data, including raw data and data products, are hosted at the CAsDC. Data resources and services of the CAsDC are introduced.

The Herschel Space Observatory carried out observations at far-infrared wavelengths, which significantly increased our knowledge of the interstellar medium and the star-formation process in the Milky Way and external galaxies, as well as our understanding of astrochemistry.

Absorption features, known, e.g., from observations at millimeter wavelengths, are more commonly observed in the far-infrared, in particular toward strong dust continuum sources. The lowest energy transitions are not only observed at LSR-velocities related to the source, but often also at velocities associated with diffuse molecular clouds along the line of sight toward the background source.

Unbiased spectral line surveys of the massive and very luminous Galactic Center sources Sagittarius B2(M) and (N) were carried out across the entire frequency range of the high-resolution Heterodyne Instrument for Far-Infrared Astronomy (HIFI). An absorption feature was detected toward both sources at about 617.531 GHz, corresponding to 20.599 cm−1, 485.47 μm, or 2.5539 meV. This feature is unique in its appearance at all velocity components associated with diffuse foreground molecular clouds, together with its conspicuous absence at velocities related to the sources themselves. The carriers of at least a substantial part of the DIBs are thought to reside in the diffuse interstellar medium. Therefore, we consider this absorption feature to be a far-infrared DIB analog.

Subsequent dedicated observations confirmed that the line is present only in the foreground clouds on the line of sight toward other massive star-forming regions in the Galactic disk. There is indication that the feature has substructure, possibly of fine or hyperfine nature. Attempts to assign the feature to atomic or molecular species have been unsuccessful so far.

The Sun is used as the fundamental standard in chemical abundance studies, thus it is important to know whether the solar abundance pattern is representative of the solar neighborhood. Albeit at low precision (0.05 – 0.10 dex) the Sun seems to be a typical solar-metallicity disk star, at high precision (0.01 dex) its abundance pattern seems abnormal when compared to solar twins. The Sun shows a deficiency of refractory elements that could be due to the formation of terrestrial planets. The formation of giant planets may also introduce a signature in the chemical composition of stars. We discuss both planet signatures and also the enhancement of neutron-capture elements in the solar twin 18 Sco.

The first extragalactic diffuse interstellar band (DIB) detections were of λ4430 in the Large and Small Magellanic Clouds (LMC and SMC) in the 1960s and 70s. Driven mainly by the increased sensitivity afforded by 8-10 m-class telescopes, the last 13 years have witnessed an explosion of DIB discoveries throughout the nearby and distant universe. This review focuses on the history of extragalactic DIB studies, including some of the important results that have come out of this field, and looks to the future for what can be learned about DIBs in external galaxies with the next generation of large telescopes. So far, DIBs have been observed in the Magellanic Clouds, starburst galaxies, DLAs, and nearby (≤30 Mpc distant) spiral galaxies, and are found to be ubiquitous in the diffuse interstellar medium (ISM) of extragalactic environments wherever dust is present. Important results include the finding that DIB carriers are significantly more closely related to dust than to neutral hydrogen, and that the λ6283 DIB tends to be anomalously weak in low-metallicity sightlines.

The formation and evolution of the heavy neutron-capture elements (Z > 37) are to date not well understood. Therefore, abundance and galactic chemical evolution (GCE) studies of these heavy elements may carry key information to this open question. Strontium (Sr) is one of the two heavy elements (Sr and Ba) that show intrinsically very strong absorption lines even in extremely metal-poor stars (and remains detectable at low spectral resolution). Hence, the 4077 Å Sr II line provides a unique insight into the behaviour of heavy neutron-capture elements at all metallicities and resolutions. Here the focus is on strontium, its 3D and NLTE (non-local thermodynamic equilibrium) corrections, as well as chemical evolution.

For the M active catalogue of Guoshoujing Telescope (LAMOST), 933 sources are presented in at least two exposures. We found that many M active stars show chromospheric variability in the Ca II H, Hα, Hβ, and Hγ lines on short or long timescales.

The electronic spectroscopy of various polycyclic aromatic hydrocarbon (PAH) molecules has been studied in the laboratory at low temperatures using both molecular beam and matrix isolation spectroscopy techniques. While molecular beam spectra can be readily compared to astronomical observations, the band positions measured in Ne and Ar matrices are extrapolated to obtain rather good estimates for the same transitions in the gas phase. Absolute absorption cross sections are determined for gas-phase and matrix spectra by comparing them with calibrated solution spectra. All laboratory results are analyzed and discussed in view of the role that PAHs can play as carriers of the diffuse interstellar bands (DIBs). Our studies suggest that regular neutral PAHs are not responsible for any of the known strong DIBs.

A one-meter wide field astronomical telescope with Alt-Az mount, putting in work at prime focus with field corrector, is located at the Nanshan site of Xinjiang Astronomical Observatory. The Nanshan One meter Wide-field Telescope (hereafter NOWT) provides excellent optical quality, pointing accuracy and tracking accuracy. The main scientific goals of NOWT are supernovae, gamma-ray bursts, novae, variable stars, and active galactic nuclei. It is worthwhile to point out that the sky background at the Nanshan is a classic optical site.

We select super high quality spectra of spectral type A, F, G, K, M stars from SDSS C DR7. We mix our spectra with noise and then measure their radial velocity. The analysis shows that the accuracy of K, M type stars is much better than A, F stars. With our relationship between the signal-to-noise and accuracy of radial velocity measurement of different spectral type, we provide a good reference for stellar study related to radial velocity.

Based on the South Galactic Cap U-band Sky Survey (SCUSS) and SDSS observation, we adopted the star-count method to analyze the stellar distribution in different directions of the Galaxy. We find that these model parameters may be variable with observed direction, which cannot simply be attributed to statistical errors.

Mixed aromatic/aliphatic organic nanoparticles (MAON) are suggested as the carrier of the unidentified infrared emission (UIE) features. The carriers of the diffuse interstellar bands (DIB) may be gas-phase molecular products released from MAON in the interstellar medium.

We present a comprehensive and sensitive unbiased survey of interstellar features in the near-UV range (3040-3700 Å). We combined a large number of VLT/UVES archival observations of a sample of highly reddened early type stars – typical diffuse interstellar band (DIB) targets. We stacked the individual observations to obtain a spectrum with a signal-to-noise ratio exceeding 1500. Careful inspection of this spectrum reveals tens of absorption features of interstellar nature, most of which can be identified with various atomic and molecular features. We furthermore detect four weak unidentified features, but we cannot establish their interstellar nature. Our sensitivity is limited by telluric and instrumental residuals; this precludes us from detecting broader features (e.g. DIBs). For each detected feature, we measured fundamental parameters (radial velocities, line widths, and equivalent widths). We also compare our co-added spectrum to cold gas-phase laboratory measurements of small, neutral polycyclic aromatic hydrocarbon (PAH) molecules.