相关论文: The Star Formation Threshold in NGC 6822

Observations in the IJKs wave bands covering the central 20'x20' of the Local Group galaxy NGC 6822 have been performed from the William Herschel Telescope in La Palma. They have allowed us to characterize, for the first time in the…

Halpha and UBV photometry of NGC 6822 are used to study the distribution of OB stars and HII regions in the galaxy and to determine whether individual regions of the galaxy are in a state of ionization balance. Four distinct components of…

In this paper, I investigate the processes that regulate the rate of star formation in regions of galaxies where the neutral interstellar medium is predominantly composed of non-star-forming HI. In such regions, found today predominantly in…

We present a demographic analysis of integrated star formation and gas properties for a sample of galaxies representative of the overall population at z~0. This research was undertaken in order to characterise the nature of star formation…

We present a wide-field, high spatial and velocity resolution map of the entire extended HI distribution of the nearby Local Group dwarf galaxy NGC 6822. The observations were obtained with the Parkes single-dish telescope and the Australia…

We present new Hubble Space Telescope Advanced Camera for Surveys imaging of six positions spanning 5.8 kpc of the HI major axis of the Local Group dIrr NGC 6822, including both the putative companion galaxy and the large HI hole. The…

Using spectra taken with the AAOmega spectrograph, we measure the radial velocities of over 100 stars, many of which are intermediate age carbon stars, in the direction of the dwarf irregular galaxy NGC 6822. Kinematic analysis suggests…

We use the IRAM HERACLES survey to study CO emission from 33 nearby spiral galaxies down to very low intensities. Using atomic hydrogen (HI) data, mostly from THINGS, we predict the local mean CO velocity from the mean HI velocity. By…

We present adaptive optics assisted integral field spectroscopy of nine Halpha-selected galaxies at z=0.84--2.23 selected from the HiZELS narrow-band survey. Our observations map the star-formation and kinematics of these representative…

(Abridged): We present U, B, V, R, I, H-alpha and NUV photometry of 14 galaxies in the very local Universe (within 10 Mpc that are dwarf irregular galaxies (dIrr), are at low redshift (51<v<610 km/s), and appear as a six degree long linear…

The far-infrared [C II] 158 micrometer fine structure transition is considered to be a dominant coolant in the interstellar medium. For this reason, under the assumption of a thermal steady state, it may be used to infer the heating rate…

The star formation histories (SFHs) of galaxies provide valuable insights into galaxy evolution and stellar physics. Understanding the SFHs enables the study of chemical enrichment of galaxies, star formation triggered by interactions, and…

We report the discovery of a threshold in the HI column density of Galactic gas clouds below which the formation of the cold phase of HI is inhibited. This threshold is at $N_{HI} = 2 \times 10^{20}$ per cm$^{2}$; sightlines with lower HI…

We study global star formation thresholds in the outer parts of galaxies by investigating the stability of disk galaxies embedded in dark halos. The disks are self-gravitating, contain metals and dust, and are exposed to UV radiation. We…

The relative distribution of molecular gas and star formation in galaxies gives insight into the physical processes and timescales of the cycle between gas and stars. In this work, we track the relative spatial configuration of CO and…

Based on the photometric properties of NGC 6822 we derive a robust star formation history. Adopting this history we compute 15 models of galactic chemical evolution. All of them match present-day photometric properties. The dark halo mass…

We measure empirical relationships between the local star formation rate (SFR) and properties of the star-forming molecular gas on 1.5 kpc scales across 80 nearby galaxies. These relationships, commonly referred to as "star formation laws,"…

We present a model that unifies the cosmic star formation rate (CSFR), obtained through the hierarchical structure formation scenario, with the (Galactic) local star formation rate (SFR). It is possible to use the SFR to generate a CSFR…

NGC 1232 is a face-on spiral galaxy and a great laboratory for the study of star-formation due to its proximity. We obtained high spatial resolution H{\alpha} images of this galaxy, with adaptive optics, using the SAM instrument at the SOAR…

We present an analysis of the star formation rate in galaxies between 0.7<z<1.8 using Near Infrared Camera and Multi-Object Spectrograph (NICMOS) grism spectral observations. We detect 163 galaxies in an area of ~4.4 square arcminutes, 37…