Deep GLIMPSE is the sixth in a series of large area projects to map regions of the Galactic plane using the Spitzer Space Telescope Infrared Array Camera (IRAC). Deep GLIMPSE is a Warm Mission Spitzer Cycle 8 Exploration Science Program (PIDs 80074 and 80253) that mapped 125 degrees of longitude of the Far Side of the Galaxy. Warm Mission Spitzer has two IRAC bands, centered at approximately 3.6 and 4.5 μm. The Galactic longitudes covered by Deep GLIMPSE are l=265◦-350◦and 25◦-65◦. The latitude width is about 2.1◦. The latitude center follows the Galactic warp at a Galactocentric distance of 13 kpc to survey the Far Outer Galaxy.
The Deep GLIMPSE Catalog (GLMDPC, or the “Catalog”) consists of the highest reliability point sources. For each IRAC band the Catalog provides fluxes (with uncertainties), positions (with uncertainties), the areal density of local point sources, the local sky brightness, and a flag that provides information on source quality and known anomalies present in the data.
The Deep Extragalactic Exploratory Probe (DEEP) is a multiphase research program dedicated to the study of the formation and evolution of galaxies and of large-scale structure in the distant universe. This paper describes the first five-year phase, denoted DEEP1. A series of 10 DEEP1 papers will discuss a range of scientific topics (e.g., the study of photometric and spectral properties of a general distant galaxy survey, the evolution observed in galaxy populations of varied morphologies). The observational basis for these studies is the Groth Survey Strip field, a 127arcmin^2^ region that has been observed with the Hubble Space Telescope (HST) in both broad I-band and V-band optical filters and with the Low Resolution Imaging Spectrograph on the Keck Telescopes. Catalogs of photometric and structural parameters have been constructed for 11,547 galaxies and stars at magnitudes brighter than 29, and spectroscopy has been conducted for a magnitude-color weighted subsample of 818 objects.
This paper presents Hubble Space Telescope WFPC2 F606W and F814W photometric structural parameters for 7450 galaxies in the "Groth Strip". These parameters are based on a two-dimensional bulge + disk surface brightness model and were obtained using an automated reduction and analysis pipeline described in detail here.
Using spectroscopic data from the Deep Extragalactic Evolutionary Probe Groth Strip Survey (DGSS), we analyze the gas-phase oxygen abundances in the warm ionized medium for 64 emission-line field galaxies in the redshift range 0.26<z<0.82. These galaxies comprise a small subset selected from among 693 objects in the DGSS. They are chosen for chemical analysis by virtue of having the strongest emission lines. Oxygen abundances relative to hydrogen are in the range 8.4<12+log(O/H)<9.0 with typical internal plus systematic measurement uncertainties of 0.17dex. The 64 DGSS galaxies collectively exhibit an increase in metallicity with B-band luminosity, i.e., an L-Z relation like that seen among local galaxies. Using the DGSS sample and local galaxy samples for comparison, we searched for a "second parameter" that might explain some of the dispersion seen in the L-Z relation. Parameters such as galaxy color, emission-line equivalent width, and effective radius were explored but found to be uncorrelated with residuals from the mean L-Z relation.
We present a candidate sample of luminous bulges (including ellipticals) found within the Groth Strip Survey (GSS), with spectroscopic redshifts of 0.73<z<1.04 from the Keck Telescope. This work is distinguished by its use of two-dimensional two-component decomposition photometry from Hubble Space Telescope (HST) images to separate the bulge from any disk before applying the sample selection and to measure disk-free colors. We define a statistically complete sample of 86 bulges with r^1/4^ profiles and luminosities brighter than I_AB_=24. Although larger samples of distant early-type galaxies exist, this is the largest and most homogeneous sample of bulges at z~1 with spectroscopy. A brighter subset of 52 objects with added structural constraints defines our "quality sample" that is used to explore bulge luminosities and colors.
We present the luminosity function and color-redshift relation of a magnitude-limited sample of 145 mostly red field E/S0 galaxies at z<~1 from the DEEP Groth Strip Survey (GSS). Using nearby galaxy images as a training set, we develop a quantitative method to classify E/S0 galaxies based on smoothness, symmetry, and bulge-to-total light ratio. Using this method, we identify 145 E/S0's at 16.5<I<22 within the GSS, for which 44 spectroscopic redshifts (z_spec_) are available. Most of the galaxies with spectroscopic redshifts (86%) form a "red envelope" in the redshift-color diagram, consistent with predictions of spectral synthesis models in which the dominant stellar population is formed at redshifts z>~1.5.
The knowledge of the point spread function (PSF) of imaging instruments represents a fundamental requirement for astronomical observations. The Herschel PACS PSFs delivered by the instrument control centre are obtained from observations of the Vesta asteroid, providing a characterisation of the central part therefore excluding fainter features. However, inumany cases information on both the core and the wings of the PSFs is needed. With this aim, we combine Vesta and Mars dedicated observations and obtain PACS PSFs with an unprecedented dynamic range (~10^6^), at slow and fast scan speeds and for the three photometric bands.
We present a 74MHz survey of a 165deg^2^ region located near the north Galactic pole. This survey has an unprecedented combination of both resolution (25" FWHM) and sensitivity ({sigma} as low as 24mJy/beam). We detect 949 sources at the 5{sigma} level in this region, enough to begin exploring the nature of the 74MHz source population. We present differential source counts, spectral index measurements, and the size distribution as determined from counterparts in the high-resolution FIRST 1.4GHz survey, Cat. <VIII/71>.
Leo T is the lowest mass gas-rich galaxy currently known and studies of its gas content help us understand how such marginal galaxies survive and form stars. We present deep neutral hydrogen (HI) observations from the Westerbork Synthesis Radio Telescope in order to understand its HI distribution and potential for star formation. We find a larger HI line flux than the previously accepted value, resulting in a 50% larger HI mass of 4.1x10^5^M_{sun}_. The additional HI flux is from low surface brightness emission that was previously missed; with careful masking this emission can be recovered even in shallower data.We perform a Gaussian spectral decomposition to find a cool neutral medium component (CNM) with a mass of 3.7x10^4^M_{sun}_, or almost 10% of the total HI mass. Leo T has no HI emission extending from the main HI body, but there is evidence of interaction with the Milky Way circumgalactic medium in both a potential truncation of the HI body and the offset of the peak HI distribution from the optical center. The CNM component of Leo T is large when compared to other dwarf galaxies, even though Leo T is not currently forming stars and has a lower star formation efficiency than other gas-rich dwarf galaxies. However, the HI column density associated with the CNM component in Leo T is low. One possible explanation is the large CNM component is not related to star formation potential but rather a recent, transient phenomenon related to the interaction of Leo T with the Milky Way circumgalactic medium.
Kalirai et al. have observed the globular cluster 47 Tucanae for 121 orbits using the Advanced Camera for Surveys. These extremely deep images were taken in two filters: F606W (broad V-band) and F814W (I-band). Using these observations, Kalirai et al. were able to construct one of the deepest and most complete color-magnitude diagrams of a stellar population, probing down to 30th magnitude and extending from the faintest end of the main sequence to the coolest white dwarf members. As an added bonus, members of the Small Magellanic Cloud represent background sources, and these observations are able to resolve SMC targets down to 0.2 solar masses.
The team have released their stacked ACS mosaics (FITS files), source catalog (ASCII text table), and artificial source lists (ASCII text table) used for testing photometry, astrometry, and completeness, as High Level Science Products. We summarize the creation of the stacked images and generation of the catalogs below, but refer you to the original publication for complete details.
All available catalogs are listed at http://archive.stsci.edu/vo/mast_services.html.
![To the extent possible under law, the publisher has waived all copyright and related or neighboring rights to the catalogue of astrometric microlensing events. For details, see the `Creative Commons CC0 1.0 Public Domain dedication <http://creativecommons.org/publicdomain/zero/1.0/>`_. Of course, you should still give proper credit when using this data as required by good scientific practice. .. image:: /static/img/cc0.png :alt: [CC0]](/registry-search/?f%5BcapabilityType_facet%5D%5B%5D=Simple+Cone+Search&f%5Brights_facet%5D%5B%5D=To+the+extent+possible+under+law%2C+the+publisher+has+waived+all+copyright+and+related+or+neighboring+rights+to+the+catalogue+of+astrometric+++microlensing+events.++For+details%2C+see+the+%60Creative+Commons+CC0+1.0+Public+Domain+dedication+%3Chttp%3A%2F%2Fcreativecommons.org%2Fpublicdomain%2Fzero%2F1.0%2F%3E%60_.++Of+course%2C+you+should+still+give+proper+credit+when+using+this+data+as+required+by+good+scientific+practice.%0A%0A..+image%3A%3A+%2Fstatic%2Fimg%2Fcc0.png%0A+++%3Aalt%3A+%5BCC0%5D%0A%0A){kind=link}