Spitzer IRS observations of k plus a galaxies: a link between polycyclic aromatic hydrocarbon emission properties and active galactic nucleus feedback?

We have performed Spitzer InfraRed Spectrograph (IRS) low-resolution 5-12 mu m spectroscopy on a sample of galaxies selected to be at three distinct poststarburst evolutionary stages based on their optical spectral indices. The resulting IRS spectra show distinctive polycyclic aromatic hydrocarbon (PAH) emission line structures at 6.2, 7.7, 8.6, and 11.3 mu m and little silicate absorption, indicative of ongoing star formation. However, the PAH interline ratios, in particular the 11.3/6.2 mu m and 7.7/6.2 mu m ratio, show large variations. These variations are found to correlate with both time since the most recent starburst and active galactic nucleus (AGN) activity. We speculate that the evolution observed in these PAH ratios is related to an increase in AGN activity with time since starburst

HST imaging of hyperluminous infrared galaxies

We present HST WFPC2 I band imaging for a sample of 9 Hyperluminous Infrared Galaxies spanning a redshift range 0.45 < z < 1.34. Three of the sample have morphologies showing evidence for interactions, six are QSOs. Host galaxies in the QSOs are reliably detected out to z ~ 0.8. The detected QSO host galaxies have an elliptical morphology with scalelengths spanning 6.5 < r_{e}(Kpc) < 88 and absolute k corrected magnitudes spanning -24.5 < M_{I} < -25.2. There is no clear correlation between the IR power source and the optical morphology. None of the sources in the sample, including F15307+3252, show any evidence for gravitational lensing. We infer that the IR luminosities are thus real. Based on these results, and previous studies of HLIRGs, we conclude that this class of object is broadly consistent with being a simple extrapolation of the ULIRG population to higher luminosities; ULIRGs being mainly violently interacting systems powered by starbursts and/or AGN. Only a small number of sources whose infrared luminosities exceed 10^{13}Lsun are intrinsically less luminous objects which have been boosted by gravitational lensing.Comment: 16 Pages. Accepted for publication in MNRA

Sub-millimetre observations of hyperluminous infrared galaxies

We present sub-mm photometry for 11 Hyperluminous Infrared Galaxies (HLIRGs) and use radiative transfer models for starbursts and AGN to investigate the IR emission. In all sources both a starburst and AGN are required to explain the IR emission. The mean starburst fraction is 35%, with a range spanning 80% starburst dominated to 80% AGN dominated. In all cases the starburst dominates at rest-frame wavelengths >50 microns, with star formation rates >500 solar masses per year. The trend of increasing AGN fraction with increasing IR luminosity seen in IRAS galaxies peaks in HLIRGs, and is not higher than the fraction seen in bright ULIRGs. The AGN and starburst luminosities correlate, suggesting that a common physical factor, plausibly the dust masses, governs their luminosities. Our results suggest that the HLIRG population is comprised both of ULIRG-like galaxy mergers, and of young galaxies going through their maximal star formation periods whilst harbouring an AGN. The coeval AGN and starburst activity in our sources implies that starburst and AGN activity, and the peak starburst and AGN luminosities, can be coeval in active galaxies generally. When extrapolated to high-z our sources have comparable sub-mm fluxes to sub-mm survey sources. At least some sub-mm survey sources are therefore likely to be comprised of similar galaxy populations to those found in the HLIRG population. It is also plausible from these results that high-z sub-mm sources harbour heavily obscured AGN. The differences in X-ray and sub-mm properties between HLIRGs at z~1 and sub-mm sources at z~3 implies evolution between the two epochs. Either the mean AGN obscuration level is greater at z~3 than at z~1, or the fraction of IR-luminous sources at z~3 that contain AGN is smaller than that at z~1.Comment: 15 pages. Accepted for publication in MNRA

Learning the fundamental mid-infrared spectral components of galaxies with non-negative matrix factorization

The mid-infrared (MIR) spectra observed with the Spitzer Infrared Spectrograph (IRS) provide a valuable data set for untangling the physical processes and conditions within galaxies. This paper presents the first attempt to blindly learn fundamental spectral components of MIR galaxy spectra, using non-negative matrix factorization (NMF). NMF is a recently developed multivariate technique shown to be successful in blind source separation problems. Unlike the more popular multivariate analysis technique, principal component analysis, NMF imposes the condition that weights and spectral components are non-negative. This more closely resembles the physical process of emission in the MIR, resulting in physically intuitive components. By applying NMF to galaxy spectra in the Cornell Atlas of Spitzer/IRS sources, we find similar components amongst different NMF sets. These similar components include two for active galactic nucleus (AGN) emission and one for star formation. The first AGN component is dominated by fine structure emission lines and hot dust, the second by broad silicate emission at 10 and 18 μm. The star formation component contains all the polycyclic aromatic hydrocarbon features and molecular hydrogen lines. Other components include rising continuums at longer wavelengths, indicative of colder grey-body dust emission. We show an NMF set with seven components can reconstruct the general spectral shape of a wide variety of objects, though struggle to fit the varying strength of emission lines. We also show that the seven components can be used to separate out different types of objects. We model this separation with Gaussian mixtures modelling and use the result to provide a classification tool. We also show that the NMF components can be used to separate out the emission from AGN and star formation regions and define a new star formation/AGN diagnostic which is consistent with all MIR diagnostics already in use but has the advantage that it can be applied to MIR spectra with low signal-to-noise ratio or with limited spectral range. The seven NMF components and code for classification are available at https://github.com/pdh21/NMF_software/

Efek Probio_FM dan Larutan Kunyit terhadap Performa dan Penurunan Jumlah Campylobacter pada Itik Lokal Kerinci

ABSTRACT. Campylobacter merupakan salah satu bakteri yang terdapat dalam usus halus itik, yang dapat menurunkan performa dan menyebabkan penyakit yang bersifat zoonosis. Penularan kebanyakan terjadi melalui daging, tetapi belum ada yang memastikan bagaimana bakteri ini dapat berada pada daging, sehingga berbagai biokontrol diupayakan dalam menekan dan mencegah penularan Campylobacter. Tujuan penelitian ini untuk melihat efektivitas pemberian probiotik bakteri asam laktat, kunyit, dan gabungan keduanya dalam menekan keberadaan Campylobacter dalam usus halus, serta pengaruh pemberiannya terhadap performa itik lokal kerinci. Penelitian menggunakan Rancangan Acak Lengkap (RAL) dengan materi 100 ekor itik lokal kerinci jantan, yang mendapat perlakuan kontrol (P0); pemberian Probio_FM (P1); pemberian larutan kunyit (P2), dan gabungan Probio_FM dan larutan kunyit (P3) dalam pakan, dengan masing-masing 5 ulangan. Hasil penelitian ini menunjukkan bahwa perlakuan yang diberikan tidak berpengaruh nyata (P0,05) terhadap performa, pH, jumlah bakteri asam laktat, dan jumlah Campylobacter pada jejunum dan ileum itik kerinci. Berdasarkan hasil penelitian, dapat disimpulkan bahwa pemberian Probi_FM, larutan kunyit, dan gabungan keduanya belum mampu menekan keberadaan Campylobacter dalam usus halus itik kerinci.  (The effect of Probio FM and turmeric solution on performance and reducing Campylobacter in Kerinci local duck) ABSTRAK. Campylobacter is one of the bacteria found in the small intestine of ducks, which can reduce performance and cause zoonotic diseases. Transmission mostly occurs through meat, but no one has confirmed how this bacteria can be in the meat, so various biocontrols are treated to suppress and prevent Campylobacter transmission. This study intended to evaluate the effectiveness of lactic acid bacteria probiotics, turmeric, and their combination administrations in suppressing the presence of Campylobacter in the small intestine, as well as the effect of their administration on the performance of local kerinci ducks. The experiment used a completely randomized design (CRD) with 100 male local kerinci ducks, received control treatment (P0); administration of Probio_FM (P1); administration of turmeric solution (P2), and a combination of Probio_FM and turmeric solution (P3) in duck feed, with 5 replications respectively. The results showed that all treatments had no significant effect (P0.05) on the performance, pH, the number of lactic acid bacteria, and Campylobacter in the jejunum and ileum of kerinci ducks. It could be concluded that the administration of Probio_FM, turmeric solution, and their combination had not been able to suppress the presence of Campylobacter in the small intestine of kerinci ducks

Spectral energy distributions of quasars selected in the mid-infrared

We present preliminary results on fitting of SEDs to 142 z>1 quasars selected in the mid-infrared. Our quasar selection finds objects ranging in extinction from highly obscured, type-2 quasars, through more lightly reddened type-1 quasars and normal type-1s. We find a weak tendency for the objects with the highest far-infrared emission to be obscured quasars, but no bulk systematic offset between the far-infrared properties of dusty and normal quasars as might be expected in the most naive evolutionary schemes. The hosts of the type-2 quasars have stellar masses comparable to those of radio galaxies at similar redshifts. Many of the type-1s, and possibly one of the type-2s require a very hot dust component in addition to the normal torus emission.Comment: 4 pages, 2 figures, to appear in the proceedings of The Spectral Energy Distribution of Galaxies, Preston, September 2011, eds R.J. Tuffs & C.C. Popesc

Bilingual Palestinians' Attitudes towards Code-Switching

Prestige is a matter that concerns everyone as an attempt to follow the high class. The way people speak is one of the most noticeable factors that are used to determine if they are prestigious or not. Code-switching helps to create a new level of prestigious speech which is what we are trying to test in this study in the community of Hebron-Palestine. The purpose of this study is to investigate participants’ attitudes towards Code-switching (whether it is prestigious or not) and what reasons led to these attitudes. Data were collected from 80 members of the society from different educational levels and different age categories using a questionnaire that was sent to participants online. The study revealed that that code-switching is considered prestigious and it reflects the level of education of people in the society. Society turns out to believe that code-switching is a sign of prestige after the dramatic growth of the use of social networking. The data was analyzed using SPSS version 24. Theoretical and practical implications were discussed. Researchers hope that this study will help other linguists who are trying to search in this field

Adaptive Optics Discovery of Supernova 2004ip in the Nuclear Regions of the Luminous Infrared Galaxy IRAS 18293-3413

We report a supernova discovery in Ks-band images from the NAOS CONICA adaptive optics (AO) system on the ESO Very Large Telescope (VLT). The images were obtained as part of a near-infrared search for highly-obscured supernovae in the nuclear regions of luminous and ultraluminous infrared galaxies. SN 2004ip is located within a circumnuclear starburst at 1.4 arcsec (or 500 pc) projected distance from the K-band nucleus of the luminous infrared galaxy IRAS 18293-3413. The supernova luminosity and light curve are consistent with a core-collapse event suffering from a host galaxy extinction of up to about 40 magnitudes in V-band which is as expected for a circumnuclear starburst environment. This is the first supernova to be discovered making use of AO correction and demonstrates the potential of the current 8-meter class telescopes equipped with AO in discovering supernovae from the innermost nuclear regions of luminous and ultraluminous infrared galaxies.Comment: 4 pages, 3 figures, ApJ Letters (accepted

Automated Global Feature Analyzer - A Driver for Tier-Scalable Reconnaissance

For the purposes of space flight, reconnaissance field geologists have trained to become astronauts. However, the initial forays to Mars and other planetary bodies have been done by purely robotic craft. Therefore, training and equipping a robotic craft with the sensory and cognitive capabilities of a field geologist to form a science craft is a necessary prerequisite. Numerous steps are necessary in order for a science craft to be able to map, analyze, and characterize a geologic field site, as well as effectively formulate working hypotheses. We report on the continued development of the integrated software system AGFA: automated global feature analyzerreg, originated by Fink at Caltech and his collaborators in 2001. AGFA is an automatic and feature-driven target characterization system that operates in an imaged operational area, such as a geologic field site on a remote planetary surface. AGFA performs automated target identification and detection through segmentation, providing for feature extraction, classification, and prioritization within mapped or imaged operational areas at different length scales and resolutions, depending on the vantage point (e.g., spaceborne, airborne, or ground). AGFA extracts features such as target size, color, albedo, vesicularity, and angularity. Based on the extracted features, AGFA summarizes the mapped operational area numerically and flags targets of "interest", i.e., targets that exhibit sufficient anomaly within the feature space. AGFA enables automated science analysis aboard robotic spacecraft, and, embedded in tier-scalable reconnaissance mission architectures, is a driver of future intelligent and autonomous robotic planetary exploration

Optical integral field spectroscopy of intermediate redshift infrared bright galaxies

The extreme infrared (IR) luminosity of local luminous and ultra-luminous IR galaxies (U/LIRGs; 11 12, respectively) is mainly powered by star-formation processes triggered by mergers or interactions. While U/LIRGs are rare locally, at z > 1, they become more common, they dominate the star-formation rate (SFR) density, and a fraction of them are found to be normal disk galaxies. Therefore, there must be an evolution of the mechanism triggering these intense starbursts with redshift. To investigate this evolution, we present new optical SWIFT integral field spectroscopic H{\alpha}+[NII] observations of a sample of 9 intermediate-z (0.2 < z < 0.4) U/LIRG systems selected from Herschel 250{\mu}m observations. The main results are the following: (a) the ratios between the velocity dispersion and the rotation curve amplitude indicate that 10-25% (1-2 out of 8) might be compatible with being isolated disks while the remaining objects are interacting/merging systems; (b) the ratio between un-obscured and obscured SFR traced by H{\alpha} and LIR, respectively, is similar in both local and these intermediate-z U/LIRGs; and (c) the ratio between 250{\mu}m and the total IR luminosities of these intermediate-z U/LIRGs is higher than that of local U/LIRGs with the same LIR . This indicates a reduced dust temperature in these intermediate-z U/LIRGs. This, together with their already measured enhanced molecular gas content, suggests that the interstellar medium conditions are different in our sample of intermediate-z galaxies when compared to local U/LIRGs.Comment: Accepted for publication in MNRA