1,422 research outputs found
Discovery of an isolated compact elliptical galaxy in the field
We present the discovery of an isolated compact elliptical (cE) galaxy, found
during a search of SDSS DR7 for cEs, and for which we obtained WHT/ACAM
imaging. It is ~900 kpc distant from its nearest neighbour, has an effective
r-band radius of ~500 pc and a B-band mean surface brightness within its
effective radius of 19.75 mag/arcsec. Serendipitous deep SuprimeCam imaging
shows that there is no underlying disk. Its isolated position suggests that
there is an alternative channel to the stripping scenario for the formation of
compact ellipticals. We also report analysis of recent deeper imaging of the
previous candidate free-flying cE, which shows that it is, in fact, a normal
dwarf elliptical (dE). Hence the new cE reported here is the first confirmed
isolated compact elliptical to be found in the field.Comment: 5 pages, 6 figures. Accepted to MNRA
Impact Analysis of Malware Based on Call Network API with Heuristic Detection Method
Malware is a program that has a negative influence on computer systems that don\u27t have user permissions. The purpose of making malware by hackers is to get profits in an illegal way. Therefore, we need a malware analysis. Malware analysis aims to determine the specifics of malware so that security can be built to protect computer devices. One method for analyzing malware is heuristic detection. Heuristic detection is an analytical method that allows finding new types of malware in a file or application. Many malwares are made to attack through the internet because of technological advancements. Based on these conditions, the malware analysis is carried out using the API call network with the heuristic detection method. This aims to identify the behavior of malware that attacks the network. The results of the analysis carried out are that most malware is spyware, which is lurking user activity and retrieving user data without the user\u27s knowledge. In addition, there is also malware that is adware, which displays advertisements through pop-up windows on computer devices that interfaces with user activity. So that with these results, it can also be identified actions that can be taken by the user to protect his computer device, such as by installing antivirus or antimalware, not downloading unauthorized applications and not accessing unsafe websites.
 
Identifying Blue Horizontal Branch Stars Using the z Filter
In this paper we present a new method for selecting blue horizontal branch
(BHB) candidates based on color-color photometry. We make use of the Sloan
Digital Sky Survey z band as a surface gravity indicator and show its value for
selecting BHB stars from quasars, white dwarfs and main sequence A type stars.
Using the g, r, i, and z bands, we demonstrate that extraction accuracies on
par with more traditional u, g, and r photometric selection methods may be
achieved. We also show that the completeness necessary to probe major Galactic
structure may be maintained. Our new method allows us to efficiently select BHB
stars from photometric sky surveys that do not include a u band filter such as
the Panoramic Survey Telescope and Rapid Response System.Comment: Accepted for publication in The Astronomical Journa
Straw bale seismic design capacities 2
Straw bale is a sustainable building material that repurposes agricultural waste for use in the structural system of buildings. This material will be used as a component in the lateral force resisting systems of walls, especially helpful in the California seismic environment and under heavy wind loads. The four main components of a post-and-beam method straw bale wall are timber framing, straw bales, wire mesh, and plaster. This report will focus on the design of the exterior plaster and the design of “workhorse” and “strong” walls for simple construction and areas of higher seismic activity, respectively. Our test results will be used to validate straw bale as a viable structural material for future building code development
SDSS J122958.84+000138.0: A Compact, Optically red galaxy
We report a new compact galaxy, SDSS J122958.84+000138.0 (SDSS J1229+0001),
which has unique morphological and stellar population properties that are rare
in observations of the nearby universe. SDSS J1229+0001 has an -band
absolute magnitude (M) and half-light radius (R) of 17.75 mag
and 520 pc, respectively. Located in a fairly low density environment,
morphologically it is akin to a typical early-type galaxy as it has a smooth
appearance and red colour. But, interestingly, it possesses centrally
concentrated star forming activity with a significant amount of dust. We
present an analysis of structural and stellar population properties using
archival images and VLT/FORS2 spectroscopy. Analysis of UKIDSS H-band image
shows that the observed light distribution is better fitted with two components
S\'ersic function with inner and outer component effective radii 190 and 330
pc, respectively. Whereas, overall half-light radius measured in H-band is much
smaller compared to optical, i.e 290 pc. We prepared a Spectral Energy
Distribution (SED) from optical to FIR and interpret it to derive
star-formation rate, dust mass and stellar mass. We find that the SDSS
J1229+0001 has dust mass M = 5.1 10 M_{\sun} with a
dust to stellar mass ratio log(M/M) = 3.5. While the observed
stellar population properties are -- to some extent -- similar to that of a
typical S0 galaxy, a unified view from stellar population and structural
properties may suggests that SDSS J1229+0001 is a {\it smoking gun} example of
a compact early-type galaxy in formation.Comment: 10 pages, Accepted MNRA
Megasequence architecture of Taranaki, Wanganui, and King Country basins and Neogene progradation of two continental margin wedges across western New Zealand.
Taranaki, Wanganui and King Country basins (formerly North Wanganui Basin) have been regarded as discrete basins, but they contain a very similar Neogene sedimentary succession and much of their geological history is held in common. Analysis of the stratigraphic architecture of the fill of each basin reveals the occurrence of four 2nd order megasequences of tectonic origin. The oldest is the early-early Miocene (Otaian Stage) Mahoenui Group/megasequence, followed by the late-early Miocene (Altonian Stage) Mokau Group/megasequence (King Country Basin), both of which correspond to the lower part of the Manganui Formation in Taranaki Basin. The third is the middle to late Miocene Whangamomona Group/megasequence, and the fourth is the latest Miocene-Pleistocene Rangitikei Supergroup/megasequence, both represented in the three basins. Higher order sequences (4th, 5th, 6th), having a eustatic origin, are evident in the Whangamomona and Rangitikei megasequences, particularly those of 5th order with 41 ka periodicity. The distribution of the megasequences are shown in a series of cross-section panels built-up from well -to-well correlations, complemented by time-stratigraphic cross-sections.
The base of each megasequence is marked by marine flooding and represents a discrete phase in basin development. For the first megasequence this corresponded to rapid subsidence of the King Country Basin in a compressional setting and basement overthrusting on the Taranaki Fault, with the rapid introduction of terrigenous sediment during transgression. The Mahoenui megasequence accumulated mostly at bathyal depths; no regressive deposits are evident, having been eroded during subsequent uplift. The second (Mokau) megasequence accumulated during reverse movement on the Ohura Fault, formation of the Tarata Thrust Zone, and onlap of the basement block between the Taranaki Fault and the Patea-Tongaporutu-Herangi High (PTH). The Whangamomona megasequence accumulated during extensive reflooding of King Country Basin, onlap of the PTH High and of basement in the Wanganui Basin. This is an assymetrical sequence with a thin transgressive part (Otunui Formation) and a thick regressive part (Mount Messenger to Matemateaonga Formations). It represents the northward progradation of a continental margin wedge with bottom-set, slope-set and top-set components through Wanganui and King Country basins, with minor progradation over the PTH High and into Taranaki Basin. The Rangitikei megasequence is marked by extensive flooding at its base (Tangahoe Mudstone) and reflects the pull-down of the main Wanganui Basin depocentre. This megasequence comprises a second progradational margin wedge, which migrated on two fronts, one northward through Wanganui Basin and into King Country Basin, and a second west of the PTH High, through the Toru Trough and into the Central and Northern Grabens of Taranaki Basin and on to the Western Platform as the Giant Foresets Formation, thereby building up the modern shelf and slope.
Fifth and 6th order sequences are well expressed in the shelf deposits (top-sets) of the upper parts of the Whangamomona and Rangitikei megasequences. They typically have a distinctive sequence architecture comprising shellbed (TST), siltstone (HST) and sandstone (RST) beds. Manutahi-1, which was continuously cored, provides calibration of this sequence architecture to wireline log character, thereby enabling shelf deposits to be mapped widely in the subsurface via the wireline data for hydrocarbon exploration holes. Similar characterization of slope-sets and bottom-sets is work ongoing. The higher order (eustatic) sequences profoundly influenced the local reservoir architecture and seal properties of formations, whereas the megasequence progradation has been responsible for the regional hydrocarbon maturation and migration. Major late tilting, uplift and erosion affected all three basins and created a regional high along the eastern Margin of Taranaki Basin, thereby influencing the migration paths of hydrocarbons sourced deeper in the basin and allowing late charge of structural and possibly stratigraphic traps
Prospectives
Tiré de: Prospectives, vol. 3, no 2 (avril 1967)Titre de l'écran-titre (visionné le 24 janv. 2013
Neogene stratigraphic architecture and tectonic evolution of Wanganui, King Country, and eastern Taranaki Basins, New Zealand
Analysis of the stratigraphic architecture of the fills of Wanganui, King Country, and eastern Taranaki Basins reveals the occurrence of five 2nd order Late Paleocene and Neogene sequences of tectonic origin. The oldest is the late Eocene-Oligocene Te Kuiti Sequence, followed by the early-early Miocene (Otaian) Mahoenui Sequence, followed by the late-early Miocene (Altonian) Mokau Sequence, all three in King Country Basin. The fourth is the middle Miocene to early Pliocene Whangamomona Sequence, and the fifth is the middle Pliocene-Pleistocene Rangitikei Sequence, both represented in the three basins. Higher order sequences (4th, 5th, 6th) with a eustatic origin occur particularly within the Whangamomona and Rangitikei Sequences, particularly those of 6th order with 41 000 yr periodicity
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