scholarly journals Large Scale Structure in the Local Universe — The 2MASS Galaxy Catalog

2004 ◽  
Vol 21 (4) ◽  
pp. 396-403 ◽  
Author(s):  
Thomas Jarrett
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
Local Universe ◽  
Extended Source ◽  
Large Scale Structures ◽  
Photometric Redshift ◽  
Sky Survey ◽  
Nearby Galaxies ◽  
Scale Structures ◽  
Zone Of Avoidance

AbstractUsing twin ground-based telescopes, the Two-Micron All Sky Survey (2MASS) scanned both equatorial hemispheres, detecting more than 500 million stars and resolving more than 1.5 million galaxies in the near-infrared (1–2.2 μm) bands. The Extended Source Catalog (XSC) embodies both photometric and astrometric whole sky uniformity, revealing large scale structures in the local Universe and extending our view into the Milky Way's dust-obscured ‘Zone of Avoidance’. The XSC represents a uniquely unbiased sample of nearby galaxies, particularly sensitive to the underlying, dominant, stellar mass component of galaxies. The basic properties of the XSC, including photometric sensitivity, source counts, and spatial distribution, are presented here. Finally, we employ a photometric redshift technique to add depth to the spatial maps, reconstructing the cosmic web of superclusters spanning the sky.

scholarly journals An Obscured Galaxy Redshift Survey with FLAIR

1997 ◽  
Vol 14 (1) ◽  
pp. 126-126 ◽  
Author(s):  
K. Wakamatsu ◽  
M. Malkan ◽  
Q. A. Parker ◽  
H. Karoji
Keyword(s):  
Large Scale ◽  
Wall Structure ◽  
Galactic Centre ◽  
Large Scale Structures ◽  
Sky Survey ◽  
Centre Region ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
Scale Structures ◽  
Zone Of Avoidance

A problem for studies of large scale structures in nearby space (cz < 10,000 km s-1) is the presence of the Zone of Avoidance which is so large and wide on the sky that potentially important clusters and voids remain undetected. A prime example was the Ophiuchus cluster discovered by Wakamatsu and Malkan (1981) as a heavily obscured cD cluster close to the Galactic centre region (l = 0·5°, b = +9·5°). It is the second brightest X-ray cluster after Perseus. A hidden galaxy survey was performed by visually searching ESO/SERC Sky Survey (R and J) copy films of the region centred at l = 355°, b = +10° finding more than 4000 galaxies in six fields. Several irregular clusters adjacent to Ophiuchus were found forming a supercluster which may be connected to the Hercules supercluster by a wall structure parallel to the local supergalactic plane (Wakamatsu et al. 1994). In front of this supercluster, an 'Ophiuchus Void' is suggested (cz = 4,500 km s-1). The Ophiuchus supercluster at cz = 8,500 km s-1 is similar to the Hercules supercluster (cz = 11,000 km s-1), and extends north toward the latter supercluster.

scholarly journals A New 1.4 GHz Radio Continuum Map of the Sky South of Declination +25°

2014 ◽  
Vol 31 ◽  
Author(s):  
Mark R. Calabretta ◽  
Lister Staveley-Smith ◽  
David G. Barnes
Keyword(s):  
Large Scale ◽  
Thermal Emission ◽  
High Sensitivity ◽  
Radio Continuum ◽  
Archival Data ◽  
Large Scale Structures ◽  
Low Level ◽  
Sky Survey ◽  
Scale Structures ◽  
Zone Of Avoidance

AbstractArchival data from the HI Parkes All-Sky Survey (HIPASS) and the HI Zone of Avoidance (HIZOA) survey have been carefully reprocessed into a new 1.4 GHz continuum map of the sky south of δ = +25°. The wide sky coverage, high sensitivity of 40 mK (limited by confusion), resolution of 14.4 arcmin (compared to 51 arcmin for the Haslam et al. 408 MHz and 35 arcmin for the Reich et al. 1.4 GHz surveys), and low level of artefacts make this map ideal for numerous studies, including: merging into interferometer maps to complete large-scale structures; decomposition of thermal and non-thermal emission components from Galactic and extragalactic sources; and comparison of emission regions with other frequencies. The new map is available for download.

scholarly journals EZOA – a catalogue of EBHIS H i-detected galaxies in the northern Zone of Avoidance

2019 ◽  
Vol 489 (2) ◽  
pp. 2907-2922 ◽  
Author(s):  
A C Schröder ◽  
L Flöer ◽  
B Winkel ◽  
J Kerp
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
Dwarf Galaxies ◽  
High Rate ◽  
Infrared Images ◽  
Large Scale Structures ◽  
The Past ◽  
Northern Zone ◽  
Scale Structures ◽  
Zone Of Avoidance

ABSTRACT We present a catalogue of galaxies in the northern Zone of Avoidance (ZoA), extracted from the shallow version of the blind H i survey with the Effelsberg 100 m radio telescope, EBHIS, that has a sensitivity of 23 mJy beam−1 at 10.24 km s−1 velocity resolution. The catalogue comprises 170 detections in the region δ ≥ −5° and |b| &lt; 6°. About a third of the detections (N = 67) have not been previously recorded in H i. While 29 detections have no discernible counterpart at any wavelength other than H i, 48 detections (28 per cent) have a counterpart visible on optical or near-infrared images but are not recorded as such in the literature. New H i detections were found as close as 7.5 Mpc (EZOA J2120+45), and at the edge of the Local Volume, at 10.1 Mpc, we have found two previously unknown dwarf galaxies (EZOA J0506+31 and EZOA J0301+56). Existing large-scale structures crossing the northern ZoA have been established more firmly by the new detections, with the possibility of new filaments. We conclude that the high rate of 39 per cent new H i detections in the northern ZoA, which has been extensively surveyed with targeted observations in the past, proves the power of blind H i surveys. The full EBHIS survey, which will cover the full northern sky with a sensitivity comparable to the HIPASS survey of the southern sky, is expected to add many new detections and uncover new structures in the northern ZoA.

scholarly journals First Results from the HI Parkes Zone of Avoidance Survey

1999 ◽  
Vol 171 ◽  
pp. 331-333
Author(s):  
P.A. Henning ◽  
L. Staveley-Smith ◽  
R.C. Kraan-Korteweg ◽  
E.M. Sadler
Keyword(s):  
Large Scale ◽  
Milky Way ◽  
Large Scale Structures ◽  
First Results ◽  
Nearby Galaxies ◽  
Scale Structures ◽  
Zone Of Avoidance ◽  
Blind Search

AbstractThe HI Parkes Zone of Avoidance Survey is a 21 cm blind search with the multibeam receiver on the 64-m radiotelescope, looking for galaxies hidden behind the southern Milky Way. The first phase of the survey has uncovered 107 galaxies, two-thirds of which were previously unknown. The addition of these galaxies to existing extragalactic catalogs allows the connectivity of large-scale structures across the Zone of Avoidance within 3500 km s−1 to become evident. No nearby hidden “Andromeda-class” object was uncovered. Our census of the most dynamically important HI-bearing nearby galaxies is now complete, at least for those objects whose HI profiles are not totally buried in the Galactic HI signal. The full survey is ongoing, and is expected to produce a catalog of thousands of objects when it is finished.

scholarly journals Overview of Uncovered and Suspected Large-scale Structures behind the Milky Way

1999 ◽  
Vol 16 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Renée C. Kraan-Korteweg ◽  
Patrick A. Woudt
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
Milky Way ◽  
Far Infrared ◽  
Observational Evidence ◽  
Large Scale Structures ◽  
Galaxy Distribution ◽  
Wide Range ◽  
Scale Structures ◽  
Zone Of Avoidance

AbstractVarious dynamically important extragalactic large-scale structures in the local Universe lie behind the Milky Way. Most of these structures (predicted and unexpected) have only recently been made ‘visible’ through dedicated deep surveys at various wavelengths. The wide range of observational searches (optical, near infrared, far infrared, radio and X-ray) for galaxies in the Zone of Avoidance (ZOA) will be reviewed and the uncovered and suspected large-scale structures summarised. Particular emphasis is given to the Great Attractor region where the existence of yet another cluster is suspected (Woudt 1998). Predictions from reconstructions of the density field in the ZOA are discussed and compared with observational evidence. Although no major structures are predicted out to about v ≲ 10,000 km s−1 for which no observational evidence exists, the comparison between reconstructed density fields and the observed galaxy distribution remain important as they allow derivations of the density and biasing parameters.

Super-Large-Scale Structures in the Sloan Digital Sky Survey

2006 ◽  
Vol 6 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Xin-Fa Deng ◽  
Yi-Qing Chen ◽  
Qun Zhang ◽  
Ji-Zhou He
Keyword(s):  
Large Scale ◽  
Sloan Digital Sky Survey ◽  
Large Scale Structures ◽  
Sky Survey ◽  
Scale Structures

scholarly journals On the Environments of Giant Radio Galaxies

2021 ◽  
Author(s):  
Ting-Wen Lan ◽  
J Xavier Prochaska
Keyword(s):  
Large Scale ◽  
Radio Galaxies ◽  
Sloan Digital Sky Survey ◽  
Host Galaxies ◽  
Homogeneous Sample ◽  
Large Scale Structures ◽  
Radio Jets ◽  
Sky Survey ◽  
Scale Structures ◽  
Control Samples

Abstract We test the hypothesis that environments play a key role in enabling the growth of enormous radio structures spanning more than 700 kpc, an extreme population of radio galaxies called giant radio galaxies (GRGs). To achieve this, we explore (1) the relationships between the occurrence of GRGs and the surface number density of surrounding galaxies, including satellite galaxies and galaxies from neighboring halos, as well as (2) the GRG locations towards large-scale structures. The analysis is done by making use of a homogeneous sample of 110 GRGs detected from the LOFAR Two-metre Sky Survey in combination with photometric galaxies from the DESI Legacy Imaging Surveys and a large-scale filament catalog from the Sloan Digital Sky Survey. Our results show that the properties of galaxies around GRGs are similar with that around the two control samples, consisting of galaxies with optical colors and luminosity matched to the properties of the GRG host galaxies. Additionally, the properties of surrounding galaxies depend on neither their relative positions to the radio jet/lobe structures nor the sizes of GRGs. We also find that the locations of GRGs and the control samples with respect to the nearby large-scale structures are consistent with each other. These results demonstrate that there is no correlation between the GRG properties and their environments traced by stars, indicating that external galaxy environments are not the primary cause of the large sizes of the radio structures. Finally, regarding radio feedback, we show that the fraction of blue satellites does not correlate with the GRG properties, suggesting that the current epoch of radio jets have minimal influence on the nature of their surrounding galaxies.

scholarly journals Large scale Structure of HI in other Galaxies

1991 ◽  
Vol 144 ◽  
pp. 201-212
Author(s):  
Thijs Van Der Hulst ◽  
Jurjen Kamphuis
Keyword(s):  
Atomic Hydrogen ◽  
Large Scale ◽  
Stellar Winds ◽  
Large Scale Structures ◽  
Neutral Gas ◽  
Peculiar Velocities ◽  
Show Evidence ◽  
Supernova Explosions ◽  
Nearby Galaxies ◽  
Scale Structures

In this paper we discuss the large-scale structures (> 500 pc) of the neutral atomic hydrogen in the disk of nearby galaxies, with an emphasis on finding evidence for neutral gas features in the disk - halo interface. Most nearby galaxies studied in detail appear to have hole and shell type structures in their HI disks and several show evidence for gas at peculiar velocities, probably examples of gas streaming out of the disk into the halo. Not all of the observed phenomena can be explained by stellar winds and supernova explosions and other explanations will briefly be discussed.

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