We apply the Jeans Axisymmetric Multi-Gaussian Expansion method to the stellar kinematic maps of 40 Sa–Sd EDGE-CALIFA galaxies and derive their circular velocity curves (CVCs). The CVCs are classified using the Dynamical Classification method developed in Kalinova et al. (2015). We also calculate the observational baryon efficiency, OBE, where M*/Mb=M*/(M*+MHI+MH2) of the galaxies using their stellar mass, total neutral hydrogen mass and total molecular gas from CO luminosities. Slow-rising, Flat and Round-peaked CVC types correspond to specific OBEs, stellar and dark matter (DM) halo mass values, while the Sharp-peaked CVCs span in the whole DM halo mass range of 1011-1014M⊙.

A robust feature of turbulent fragmentation theories is a universal Salpeter like slope (2.2 -2.4), for the mass spectrum of the fragments, at the high mass end. This is so due to the scale-free nature of turbulence and gravity. There are reports of top heavy / flatter Initial Mass Functions (IMF), inferred for many regions where we expect star formation to take place in gas clouds with comparatively higher gas density. Also, a higher Star Formation Efficiency (SFE) for regions of higher gas density has been proposed, to understand the formation of bound stellar systems in which dark matter is not a significant factor affecting the internal dynamics. In turbulent fragmentation models for star formation, we do not expect the mass of the stellar cluster to influence the maximum stellar mass directly and thereby imply a relation between the maximum stellar mass and the cluster mass. However, such a relation may be expected from statistical considerations. In this context, we explore the density dependence of the IMF, that would arise due to denser clouds producing more massive clusters due to the density dependence of the SFE.

We study star formation occurring in nuclear rings of barred-spiral galaxies by using hydrodynamic simulations with the prescriptions of star formation and feedback included. In models without spiral arms, the star formation rate (SFR) in a ring exhibits a strong primary burst at early time and declines to small values at late time. The early burst is caused by a rapid gas infall due to the bar growth, consuming most of the gas inside the bar regions. On the other hand, models with spiral arms show multiple starburst activities at late time caused by arm-induced gas inflows, provided that the arm pattern speed is slower than that of the bar. The SFR in models with spirals is larger by a factor of ~ 1.4–4.0 than that in the bar-only models, with larger values corresponding to stronger and slower arms. In all models, young star clusters in nuclear ring show an azimuthal age gradient only when the SFR is small, such that younger clusters tend to locate closer to the contact points between the ring and dust lanes.

Star-formation regions in nearby galaxies provide an excellent laboratory to study star formation processes, evolution of massive stars and the properties of the surrounding interstellar medium. A wealth of information can be obtained from their spectral analysis of the emission lines and the stellar continuum. Considering these, we proposed a long-term project “Spectroscopic Observations of the Star Formation Regions in Nearby Galaxies”. The primary goal of this project is to observe spectroscopy of star formation regions in 20 nearby galaxies, with the NAOC 2.16 m telescope and the Hectospec/MMT multifiber spectrograph. With the spectra of a large sample of star formation regions, combining multi-wavelength data from UV to IR, we can investigate, understand and quantify the dust extinction, star formation rate, metal abundance, and the two-dimensional distributions of stellar population properties of nearby galaxies. It will be important for a better understanding of galaxy formation. Here we report on the observations, data reduction, and analysis of the spectra of ~ 400 star formation regions in M33, via multifiber spectroscopy with Hectospec at the MMT.

One of the main scientific goals of the Herschel Gould Belt survey is to elucidate the physical mechanisms responsible for the formation and evolution of prestellar cores in molecular clouds. In the ~11 deg2 field of Aquila imaged with Herschel/PACS-SPIRE at 70–500 μm, we have identified a complete sample of 651 starless cores, 446 of them are gravitationally-bound candidate prestellar cores. Our Herschel observations also provide an unprecedented census of filaments in the Aquila cloud and suggest an intimate connection between these filaments and the formation process of prestellar cores. Indeed, a strong correlation is found between their spatial distributions. These Herschel findings support a filamentary paradigm for the early stages of star formation, where the cores result from the gravitational fragmentation of the densest filaments.

We have made near-infrared (JHKs) imaging polarimetry toward 24 bright-rimmed clouds in the southern hemisphere in order to reveal their magnetic field structures. The obtained polarization vector maps show that the magnetic field directions inside the bright rim are different from its ambient magnetic field direction, implying that magnetic field structures just inside the ionized front of the clouds are due to the gas compression by UV radiation from nearby massive star. Our investigation into the relation between the magnetic field configuration and the shape of the cloud suggests that the magnetic field configuration affects the evolution of the cloud shape.

We present results of Herschel PACS imaging spectroscopy data toward ten massive young stellar objects taken as part of the WISH project. Our sample consists of four high mass protostellar objects (HMPOs), two hot molecular cores (HMCs), and four ultracompact HII regions (UCHIIs), and the spectra cover a broad range of wavelengths (55 to 210 μm) imaged over an ~50” field with 5×5 spaxels. By fitting the continua utilizing a modified black-body formula we estimate mass-weighted dust temperature and column density distributions of warm dust and find that UCHII regions are hottest and HMCs are most deeply embedded. We also estimate rotational temperature and column density distributions of warm CO gas using the rotational diagram analysis, which are comparable over targets in contrast to continuum results. By comparing high J CO line fluxes to the RATRAN estimates of centrally heated envelope models, we find that majority of warm CO originates from bipolar outflow shocks.

As part of the Herschel Gould Belt Survey (HGBS), the Ophiuchus molecular cloud was imaged in the submillimeter range. Here, we summarize and briefly discuss the main results.

FeLoBAL quasars may be an early evolutionary stage of merger-triggered quasar activity. We test this hypothesis using HST imaging of four FeLoBAL quasars. The host galaxy colors are consistent with early-type quiescent galaxies or heavily-obscured starbursts.

We characterise steady, one-dimensional fast and slow magnetohydrodynamic (MHD) shocks using a two-fluid model. Fast MHD shocks are magnetically driven, forcing ions to stream through the neutral gas ahead of the shock front. This magnetic precursor heats the gas sufficiently to create a large, warm transition zone where all fluid variables only weakly change in the shock front. In contrast, slow MHD shocks are driven by gas pressure where neutral species collide with ion species in a thin hot slab that closely resembles an ordinary gas dynamic shock.

We computed observational diagnostics for fast and slow shocks at velocities vs=2–4 km/s and preshock Hydrogen nuclei densities nH = 102-4 cm−3. We followed the abundances of molecules relevant for a simple oxygen chemistry and include cooling by CO, H2 and H2O. Estimates of intensities of 12CO rotational lines show that high-J lines, above J = 6 → 5, are more strongly excited in slow MHD shocks.

Single-dish observations in CS(J=7-6) using the Atacama Submillimeter Telescope Experiment (ASTE) reveal emission extending out to thousands of AU from low-mass protostars, much larger than is expected based on simple models for their envelopes. Hypotheses for this emission invoke gas dispersed from the envelope surfaces facing the bipolar outflow cavities. Here, we combine interferometric data from the Submillimeter Array (SMA) with the previous single-dish data from ASTE for the low-mass protostar L483 to study the spatial-kinematic structure of its CS(J=7-6) emission on projected scales ≳600 AU. In addition to providing more detailed information for the extended component, our combined maps reveal a compact central component in CS(J=7-6) having a steeper velocity gradient. Both the compact and extended components exhibit a velocity gradient in the opposite sense to that of a bipolar molecular outflow traced in CO(J=2-1). Finding that previous models make a number of wrong predictions for the observed features, we propose that both CS(J=7-6) components are produced by rotating and infalling gas along the envelope surfaces exposed by the bipolar outflow and therefore subjected to stellar irradiation and outflow compression.

The Planck satellite has mapped the polarized microwave sky (from 30 GHz to 353 GHz) with unprecedented sensitivity and angular resolution. This wealth of data yields the first complete map of polarized thermal emission from dust in our own Galaxy, shedding new light on the formation of dense cold structures within which new stars and planetary systems are born, under the combined effects of gravity, turbulence and magnetic fields. We present a statistical analysis of this polarized emission from nearby molecular clouds, with an emphasis on the evolution of the maximum polarization fraction observed as a function of column density, and on the anti-correlation between the polarization fraction and the local dispersion of polarization angles. To interpret this data, numerical simulations of anisotropic MHD turbulence underline the essential role played by the topology of the interstellar magnetic field, in particular its large-scale component. As an extension to this work published in Planck Intermediate Results XX (A&A, 576, 105, 2015), the statistical properties of the random component of the interstellar magnetic field are explored using a toy model based on fractional Brownian motion (fBm) fields.

Submillimetre observations of externally irradiated low-mass protostellar envelopes show that the gas temperature in the envelopes is dominated by the external irradiation. Detailed studies of the protostar IRS7B in Corona Australis also show that the chemistry is strongly affected by the irradiation, depleting the abundances of complex organic molecules.

We exploit the Herschel Extragalactic Multi-Tiered Survey (HerMES) dataset along with ancillary multi-wavelength photometry and spectroscopy from the Spitzer Data Fusion to provide the most accurate determination to date of the local (0.02<z<0.5) Far-Infrared Luminosity and Star Formation Rate Function. We present and compare our results with model predictions as well as other multi-wavelength estimates of the local star formation rate density.

The Herschel Space Observatory was the fourth cornerstone mission in the European Space Agency (ESA) science programme with excellent broad band imaging capabilities in the sub-mm and far-infrared part of the spectrum. Although the spacecraft finished its observations in 2013, it left a large legacy dataset that is far from having been fully scrutinised and still has a large potential for new scientific discoveries. This is specifically true for the photometric observations of the PACS and SPIRE instruments. Some source catalogues have already been produced by individual observing programs, but there are many observations that risk to remain unexplored. To maximise the science return of the SPIRE and PACS data sets, we are in the process of building the Herschel Point Source Catalogue (HPSC) from all primary and parallel mode observations. Our homogeneous source extraction enables a systematic and unbiased comparison of sensitivity across the different Herschel fields that single programs will generally not be able to provide. The catalogue will be made available online through archives like the Herschel Science Archive (HSA), the Infrared Science Archive (IRSA), and the Strasbourg Astronomical Data Center (CDS).

Clustering analysis indicate that at z ~ 2 submm-selected galaxies (SMGs) reside in very massive halos (MDM > 5 × 1013), suggesting that SMGs trace high-density environments that evolve into rich galaxy clusters. Conversely, recent work suggests that SMGs are tracers of a broader range of environments, including structures with more modest masses caught in highly active periods; since galaxies in these structures are likely caught during episodes of peak starbursts, SMGs may be tracers of a wider range of environments beyond the progenitors of todays very rich clusters, opening a window for a more complete exploration of the details underpinning the process of galaxy evolution in concert with the assembly of the large scale structure (LSS). We have undertaken a large observing program comprising deep narrow-band Ly-alpha imaging and multi-object spectroscopy using Palomar/Keck/Magellan/Gemini telescopes to probe for galaxy overdensities in SMG environments at z ~ 1 − 5. With ~200 spectroscopically-confirmed Ly-alpha emitters, we are in a position to gauge the level of galaxy overdensity in these regions.

The nearby (d = 19.7 Mpc) Seyfert galaxy NGC 3079 exhibits a prominent bubble emerging from the nucleus. In order to investigate the nuclear power source, we carried out ammonia observations toward the center of NGC 3079 with the Tsukuba 32-m telescope and the JVLA. The NH3 (J,K) = (1, 1) through (6, 6) lines were detected in absorption at the center of NGC 3079 with the JVLA, although the profile of NH3 (3, 3) was in emission in contrast to the other transitions. All ammonia absorption lines have two distinct velocity components: one is at the systemic velocity (Vsys ~ 1116 km s−1) and the other is blueshifted (Vsys ~ 1020 km s−1), and both components are aligned along the nuclear jets. The blueshifted NH3 (3, 3) emission can be regarded as ammonia masers associated with shocks by strong winds probably from newly formed massive stars or supernova explosions in the nuclear megamaser disk. The derived rotational temperature, Trot = 120 ± 12 K for the systemic component and Trot = 157 ± 19 K for the blueshifted component, and fractional abundance of NH3 relative to molecular hydrogen H2 are higher than those in other galaxies reported. The high temperature environment at the center may be mainly attributed to heating by the nuclear jets.

We studied molecular gas properties in a sample of 98 Hi - flux selected spiral galaxies within ~ 25 Mpc using the CO J = 3 − 2 line, observed with the JCMT, and subdivided into isolated, group, and Virgo subsamples. We find a larger mean H2 mass in the Virgo galaxies compared to group galaxies, despite their lower mean Hi mass. Combining our data with complementary Hα star formation rate measurements, Virgo galaxies have a longer molecular gas depletion times compared to group galaxies, perhaps due to heating processes in the cluster environment or differences in the turbulent pressure.

The Planck satellite has provided an unprecedented view of the submm sky, allowing us to search for the dust emission of Galactic cold sources. Combining Planck-HFI all-sky maps in the high frequency channels with the IRAS map at 100um, we built the Planck catalogue of Galactic Cold Clumps (PGCC, Planck 2015 results. XXVIII), counting 13188 sources distributed over the whole sky, and following mainly the Galactic structures at low and intermediate latitudes. This is the first all-sky catalogue of Galactic cold sources obtained with a single instrument at this resolution and sensitivity, which opens a new window on star-formation processes in our Galaxy.

We present the 12CO J=1–0, 13CO J=1–0, and C18O J=1–0 maps of the M17 giant molecular clouds (GMCs) obtained as a part of the Nobeyama 45m CO Galactic Plane Survey. The observations cover the entire area of M17 SW and M17 N clouds at an angular resolution of ~ 15″ which corresponds to ~ 0.15 pc. We found that the N cloud consists of a couple of twisted filaments, they are extended in parallel toward the Hii region. The typicall width of the filaments is ~0.5 pc in 13CO intensity map. Most of young stellar objects (YSOs) are located on the filaments which have a bright rim structure in 8μm at the filament edge facing the Hii region. Furthermore, the time scale of the YSOs formation on the bright rim is comparable with that of NGC 6618 cluster which provides UV photons for the region. This fact indicates that the cluster triggered to form YSOs in N cloud. We also investigated the geometry of the Hii region and GMCs by comparing spatial distribution of 12CO velocity channel map and infrared dark cloud, and then found that NGC 6618 is possibly formed by the cloud cloud colision.