Data Release Research Papers - Academia.edu (original) (raw)

The INT Galactic Plane Survey (IGAPS) is the merger of the optical photometric surveys, IPHAS and UVEX, based on data from the Isaac Newton Telescope (INT) obtained between 2003 and 2018. Here, we present the IGAPS point source catalogue.... more

The INT Galactic Plane Survey (IGAPS) is the merger of the optical photometric surveys, IPHAS and UVEX, based on data from the Isaac Newton Telescope (INT) obtained between 2003 and 2018. Here, we present the IGAPS point source catalogue. It contains 295.4 million rows providing photometry in the filters, i, r, narrow-band Hα, g, and URGO. The IGAPS footprint fills the Galactic coordinate range, |b| < 5° and 30° < ℓ < 215°. A uniform calibration, referred to as the Pan-STARRS system, is applied to g, r, and i, while the Hα calibration is linked to r and then is reconciled via field overlaps. The astrometry in all five bands has been recalculated in the reference frame of Gaia Data Release 2. Down to i ∼ 20 mag (Vega system), most stars are also detected in g, r, and Hα. As exposures in the r band were obtained in both the IPHAS and UVEX surveys, typically a few years apart, the catalogue includes two distinct r measures, rI and rU. The r 10σ limiting magnitude is approximat...

We measure four different types of alignment signals using the galaxy groups of the Sloan Digital Sky Survey Data Release 4 to probe the impact of large scale environment on the distribution of satellite galaxies, on the the orientation... more

We measure four different types of alignment signals using the galaxy groups of the Sloan Digital Sky Survey Data Release 4 to probe the impact of large scale environment on the distribution of satellite galaxies, on the the orientation of the central and satellite galaxies: (1) the alignment between the distributions of the satellites relative to the direction of the nearest neighbor group (NNG); (2) the alignment between the major axis direction of the central galaxy of the host group (HG) and the direction of the NNG; (3) the alignment between the two major axes of the central galaxies of the HG and NNG; and (4) the alignment between the major axes of the satellites of the HG and the direction of the NNG. We find strong alignment signals of satellite distribution and orientation of central galaxy relative to the direction of the NNG even when the NNG locates beyond 3rrmvir3r_{\rm vir}3rrmvir of the host group. The alignment signals are stronger for groups that are more massive and with early type central galaxies. For the orientation of satellite galaxies, however, we do not find any significant alignment signals relative to the direction of the NNG. From these four types of the alignment measures, we conclude that the large scale environment traced by the nearby group mainly impacts the shape of the host dark matter halo, hence impacts the distribution of satellite galaxies and the orientation of central galaxies. Apart from these, there is additional impacts by the large scale environment directly onto the distribution of satellite galaxies.

In this poster line strength indices for new Single Stellar Populations (SSP) based on the recent stellar models with chemical compositions enhanced in the alpha-elements (Salasnich et al. 2000) are presented. The SSP indices have been... more

In this poster line strength indices for new Single Stellar Populations (SSP) based on the recent stellar models with chemical compositions enhanced in the alpha-elements (Salasnich et al. 2000) are presented. The SSP indices have been calculated taking into account different methods to correct the "Standard-Worthey Indices" for the real chemical composition of alpha-enhanced isochrones.

We present a study of remarkably luminous and unique dwarf galaxies at redshifts of 0.5 <z< 0.7, selected from the DEEP2 Galaxy Redshift survey by the presence of the temperature sensitive [OIII]λ4363 emission line. Measurements of... more

We present a study of remarkably luminous and unique dwarf galaxies at redshifts of 0.5 <z< 0.7, selected from the DEEP2 Galaxy Redshift survey by the presence of the temperature sensitive [OIII]λ4363 emission line. Measurements of this important auroral line, as well as other strong oxygen lines, allow us to estimate the integrated oxygen abundances of these galaxies accurately without being subject to the degeneracy inherent in the standardR23system used by most studies. [O/H] estimates range between 1/5–1/10 of the solar value. Not surprisingly, these systems are exceedingly rare and hence represent a population that is not typically present in local surveys such as SDSS, or smaller volume deep surveys such as GOODS.Our low-metallicity galaxies exhibit many unprecedented characteristics. With B-band luminosities close to L*, thse dwarfs lie significantly away from the luminosity-metallicity relationships of both local and intermediate redshift star-forming galaxies. Using s...

Stellar evolution calculations with variable abundance ratios were used to gauge the effects on temperatures, luminosities, and lifetimes in various phases. The individual elements C, N, O, Mg, Si, and Fe were included. Most of the effect... more

Stellar evolution calculations with variable abundance ratios were used to gauge the effects on temperatures, luminosities, and lifetimes in various phases. The individual elements C, N, O, Mg, Si, and Fe were included. Most of the effect relevant to integrated light models is contained in the temperature variable, as opposed to the time-scale or luminosity. We derive a recipe for including abundance-sensitive temperature effects that is applicable to existing isochrone grids. The resultant enhanced isochrones are incorporated into composite stellar population models and compared with galaxy data from the Sloan Digital Sky Survey. A severe oxygen–age degeneracy is apparent, 2–3 Gyr per 0.1 dex in [O/R], where R represents a heavy element such as Fe. Over the range of early-type galaxy velocity dispersion, the spans of all abundance ratios are reduced but the age range increases and becomes systematically older. Allowing Fe-peak elements the freedom to vary accentuates this increase ...

Over the past decade, the rapidly decreasing cost of computer storage and the increasing prevalence of high-speed Internet connections have fundamentally altered the way in which scientific research is conducted. Led by scientists in... more

Over the past decade, the rapidly decreasing cost of computer storage and the increasing prevalence of high-speed Internet connections have fundamentally altered the way in which scientific research is conducted. Led by scientists in disciplines such as genomics, the rapid sharing of data sets and cross-institutional collaboration promise to increase scientific efficiency and output dramatically. As a result, an increasing number of public “commons” of scientific data are being created: aggregations intended to be used and accessed by researchers worldwide. Yet, the sharing of scientific data presents legal, ethical and practical challenges that must be overcome before such science commons can be deployed and utilized to their greatest potential. These challenges include determining the appropriate level of intellectual property protection for data within the commons, balancing the publication priority interests of data generators and data users, ensuring a viable economic model for...