We present a 3D map of extinction in the northern Galactic plane derived using photometry from the INT/WFC Photometric Hα Survey of the northern Galactic plane. The map has fine angular ( ∼ 10 ...arcmin) and distance (100 pc) sampling allied to a significant depth (≳5 kpc). We construct the map using a method based on a hierarchical Bayesian model described in a previous article by Sale. In addition to mean extinction, we also measure differential extinction, which arises from the fractal nature of the interstellar medium, and show that it will be the dominant source of uncertainty in estimates of extinction to some arbitrary position. The method applied also furnishes us with photometric estimates of the distance, extinction, effective temperature, surface gravity, and mass for ∼38 million stars. Both the extinction map and the catalogue of stellar parameters are made publicly available via http://www.iphas.org/extinction.
Fast X-ray Transients (FXTs) are believed to be non-recurrent bright X-ray sources lasting less than a day and occuring at serendipitous positions, they can best be detected and discovered by ...instruments having a sufficiently wide field of view and high sensitivity. The IBIS/ISGRI instrument onboard INTEGRAL is particularly suited to detect new or already known fast X-ray transient sources. We report on IBIS/ISGRI detection of newly discovered outbursts of three fast transient sources located at low Galactic latitude: SAX J1818.6-1703; IGR J16479-4514; IGR J17391-302/XTE J1739-302. The reported results confirm and strengthen the very fast transient nature of these sources, given that all their newly detected outbursts have a duration less than ~3 h. Additionally, they provide the first evidence for a possible recurrent fast transient behaviour as all three sources were detected in outburst by ISGRI more than once during the last 2 years.
SN 2011ja was a bright (I = −18.3) Type II supernova occurring in the nearby edge on spiral galaxy NGC 4945. Flat-topped and multipeaked H α and H β spectral emission lines appear between 64 and 84 d ...post-explosion, indicating interaction with a disc-like circumstellar medium inclined ∼45° from edge-on. After day 84, an increase in the H- and K-band flux along with heavy attenuation of the red wing of the emission lines are strong indications of early dust formation, likely located in the cool dense shell created between the forward shock of the SN ejecta and the reverse shock created as the ejecta plows into the existing circumstellar material. Radiative transfer modelling reveals both ≈1 × 10−5 M⊙ of pre-existing dust located ∼1016.7 cm away and up to ≈6 × 10−4 M⊙ of newly formed dust. Spectral observations after 1.5 yr reveal the possibility that the fading SN is located within a young (3–6 Myr) massive stellar cluster, which when combined with tentative 56Ni mass estimates of 0.2 M⊙ may indicate a massive (≥25 M⊙) progenitor for SN 2011ja.
The INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is a 1800 deg2 imaging survey covering Galactic latitudes |b| < 5° and longitudes ℓ = 30°–215° in the r, i, and Hα filters ...using the Wide Field Camera (WFC) on the 2.5-m Isaac Newton Telescope (INT) in La Palma. We present the first quality-controlled and globally calibrated source catalogue derived from the survey, providing single-epoch photometry for 219 million unique sources across 92 per cent of the footprint. The observations were carried out between 2003 and 2012 at a median seeing of 1.1 arcsec (sampled at 0.33 arcsec pixel−1) and to a mean 5σ depth of 21.2 (r), 20.0 (i), and 20.3 (Hα) in the Vega magnitude system. We explain the data reduction and quality control procedures, describe and test the global re-calibration, and detail the construction of the new catalogue. We show that the new calibration is accurate to 0.03 mag (root mean square) and recommend a series of quality criteria to select accurate data from the catalogue. Finally, we demonstrate the ability of the catalogue's unique (r − Hα, r − i) diagram to (i) characterize stellar populations and extinction regimes towards different Galactic sightlines and (ii) select and quantify Hα emission-line objects. IPHAS is the first survey to offer comprehensive CCD photometry of point sources across the Galactic plane at visible wavelengths, providing the much-needed counterpart to recent infrared surveys.
The luminous Type IIn SN 2010jl shows strong signs of interaction between the SN ejecta and dense circumstellar material. Dust may be present in the unshocked ejecta; the cool, dense shell (CDS) ...between the shocks in the interaction region; or in the circumstellar medium (CSM). We present and model new optical and infrared photometry and spectroscopy of SN 2010jl from 82 to 1367 days since explosion. We evaluate the photometric and spectroscopic evolution using the radiative transfer codes mocassin and damocles, respectively. We propose an interaction scenario and investigate the resulting dust formation scenarios and dust masses. We find that SN 2010jl has been continuously forming dust based on the evolution of its infrared emission and optical spectra. There is evidence for preexisting dust in the CSM as well as new dust formation in the CDS and/or ejecta. We estimate that 0.005-0.01 M of predominantly carbon dust grains has formed in SN 2010jl by ∼1400 days post-outburst.
As part of surveillance of snail-borne trematodiasis in Knowsley Safari (KS), Prescot, United Kingdom, a collection was made in July 2021 of various planorbid (n = 173) and lymnaeid (n = 218) snails. ...These were taken from 15 purposely selected freshwater habitats. In the laboratory emergent trematode cercariae, often from single snails, were identified by morphology with a sub-set, of those most accessible, later characterized by cytochrome oxidase subunit 1 (cox1) DNA barcoding. Two schistosomatid cercariae were of special note in the context of human cercarial dermatitis (HCD), Bilharziella polonica emergent from Planorbarius corneus and Trichobilharzia spp. emergent from Ampullacaena balthica. The former schistosomatid was last reported in the United Kingdom over 50 years ago. From cox1 analyses, the latter likely consisted of two taxa, Trichobilharzia anseri, a first report in the United Kingdom, and a hitherto unnamed genetic lineage having some affiliation with Trichobilharzia longicauda. The chronobiology of emergent cercariae from P. corneus was assessed, with the vertical swimming rate of B. polonica measured. We provide a brief risk appraisal of HCD for public activities typically undertaken within KS educational and recreational programmes.
The luminosity determination for the ATLAS detector at the LHC during
pp
collisions at
s
=
8 TeV in 2012 is presented. The evaluation of the luminosity scale is performed using several luminometers, ...and comparisons between these luminosity detectors are made to assess the accuracy, consistency and long-term stability of the results. A luminosity uncertainty of
δ
L
/
L
=
±
1.9
%
is obtained for the
22.7
fb
-
1
of
pp
collision data delivered to ATLAS at
s
=
8 TeV in 2012.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
SN 2007od exhibits characteristics that have rarely been seen in a Type IIP supernova (SN). Optical V-band photometry reveals a very steep brightness decline between the plateau and nebular phases of ...{approx}4.5 mag, likely due to SN 2007od containing a low mass of {sup 56}Ni. The optical spectra show an evolution from normal Type IIP with broad H{alpha} emission, to a complex, four-component H{alpha} emission profile exhibiting asymmetries caused by dust extinction after day 232. This is similar to the spectral evolution of the Type IIn SN 1998S, although no early-time narrow ({approx}200 km s{sup -1}) H{alpha} component was present in SN 2007od. In both SNe, the intermediate-width H{alpha} emission components are thought to arise in the interaction between the ejecta and its circumstellar medium (CSM). SN 2007od also shows a mid-infrared excess due to new dust. The evolution of the H{alpha} profile and the presence of the mid-IR excess provide strong evidence that SN 2007od formed new dust before day 232. Late-time observations reveal a flattening of the visible light curve. This flattening is a strong indication of the presence of a light echo, which likely accounts for much of the broad, underlying H{alpha} component seen at late times. We believe that the multi-peaked H{alpha} emission is consistent with the interaction of the ejecta with a circumstellar ring or torus (for the inner components at {+-}1500 km s{sup -1}) and a single blob or cloud of circumstellar material out of the plane of the CSM ring (for the outer component at -5000 km s{sup -1}). The most probable location for the formation of new dust is in the cool dense shell created by the interaction between the expanding ejecta and its CSM. Monte Carlo radiative transfer modeling of the dust emission from SN 2007od implies that up to {approx}4 x 10{sup -4} M{sub sun} of new dust has formed. This is similar to the amounts of dust formed in other core-collapse supernovae such as SNe 1999em, 2004et, and 2006jc.
IPHASXJ194359.5+170901 is a new high-excitation planetary nebula with remarkable characteristics. It consists of a knotty ring expanding at a speed of 28 kms-1, and a fast collimated outflow in the ...form of faint lobes and caps along the direction perpendicular to the ring. The expansion speed of the polar caps is 100 kms-1, and their kinematical age is twice as large as the age of the ring. Time-resolved photometry of the central star of IPHASXJ194359.5+170901 reveals a sinusoidal modulation with a period of 1.16 d. This is interpreted as evidence for binarity of the central star, the brightness variations being related to the orbital motion of an irradiated companion. This is supported by the spectrum of the central star in the visible range, which appears to be dominated by emission from the irradiated zone, consisting of a warm (6000-7000 K) continuum, narrow Ciii, Civ and Niii emission lines, and broader lines from a flat Hi Balmer sequence in emission. IPHASXJ194359.5+170901 helps to clarify the role of (close) binaries in the formation and shaping of planetary nebulae (PNe). The output of the common-envelope (CE) evolution of the system is a strongly flattened circumstellar mass deposition, a feature that seems to be distinctive of this kind of binary system. Also, IPHASXJ194359.5+170901 is among the first post-CE PNe for which the existence of a high-velocity polar outflow has been demonstrated. Its kinematical age might indicate that the polar outflow is formed before the CE phase. This points to mass transfer on to the secondary as the origin, but alternative explanations are also considered. PUBLICATION ABSTRACT
SN 2008S erupted in early 2008 in the grand design spiral galaxy NGC 6946. The progenitor was detected by Prieto et al. in Spitzer Space Telescope images taken over the four years prior to the ...explosion, but was not detected in deep optical images, from which they inferred a self-obscured object with a mass of about 10 M⊙. We obtained Spitzer observations of SN 2008S 5 days after its discovery, as well as coordinated Gemini and Spitzer optical and infrared observations 6 months after its outburst. We have constructed radiative transfer dust models for the object before and after the outburst, using the same r−2 density distribution of pre-existing amorphous carbon grains for all epochs and taking light travel time effects into account. We rule out silicate grains as a significant component of the dust around SN 2008S. The inner radius of the dust shell moved outwards from its pre-outburst value of 85 au to a post-outburst value of 1250 au, attributable to grain vaporization by the light flash from SN 2008S. Although this caused the circumstellar extinction to decrease from AV= 15 before the outburst to 0.8 after the outburst, we estimate that less than 2 per cent of the overall circumstellar dust mass was destroyed. The total mass-loss rate from the progenitor star is estimated to have been 0.5–1.0 × 10−4 M⊙ yr−1. The derived dust-mass-loss rate of 5 × 10−7 M⊙ yr−1 implies a total dust injection into the interstellar medium of up to 0.01 M⊙ over the suggested duration of the self-obscured phase. We consider the potential contribution of objects like SN 2008S to the dust enrichment of galaxies.
PDF
