scholarly journals Numerical simulations of wind-driven protoplanetary nebulae. II. signatures of atomic emission

2019 ◽  
Author(s):  
Igor Novikov ◽  
Michael Smith
Keyword(s):  
Near Infrared ◽  
Ambient Medium ◽  
Atomic Emission ◽  
Hydrodynamic Simulations ◽  
Protoplanetary Nebulae ◽  
Atomic Medium ◽  
Protoplanetary Nebula ◽  
Shell Fragments ◽  
Oblique Shocks

Abstract We follow up on our systematic study of axisymmetric hydrodynamic simulations of protoplanetary nebula. The aim of this work is to generate the atomic analogues of the H2 near-infrared models of Paper I with the ZEUS code modified to include molecular and atomic cooling routines. We investigate stages associated with strong $\mathrm{[Fe\, {\small II}] \, 1.64\, \mathrm{\mu m} }$ and $\mathrm{ [S\, {\small II}] \, 6716}$ Å forbidden lines, the $\mathrm{[O\, {\small I}]\, 6300}$ Å airglow line, and Hα 6563 Å emission. We simulate (80 ∼ 200 km s−1) dense (∼105 cm−3) outflows expanding into a stationary ambient medium. In the case of an atomic wind interacting with an atomic medium, a decelerating advancing turbulent shell thickens with time. This contrasts with all other cases where a shell fragments into a multitude of cometary-shaped protrusions with weak oblique shocks as the main source of gas excitation. We find that the atomic wind-ambient simulation leads to considerably higher excitation, stronger peak and integrated atomic emission as the nebula expands. The weaker emission when one component is molecular is due to the shell fragmentation into fingers so that the shock surface area is increased and oblique shocks are prevalent. Position-velocity diagrams indicate that the atomic-wind model may be most easy to distinguish with more emission at higher radial velocities. With post-AGB winds and shells often highly obscured and the multitude of configurations that are observed, this study suggests and motivates selection criteria for new surveys.

scholarly journals Follow-up near-infrared spectroscopy of ultraluminous infrared galaxies observed by ISO

2005 ◽  
Vol 441 (3) ◽  
pp. 999-1010 ◽  
Author(s):  
H. Dannerbauer ◽  
D. Rigopoulou ◽  
D. Lutz ◽  
R. Genzel ◽  
E. Sturm ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Infrared Galaxies ◽  
Ultraluminous Infrared Galaxies

scholarly journals Identification of AGN in the XMM-Newton X-ray survey of the SMC

2019 ◽  
Vol 622 ◽  
pp. A29 ◽  
Author(s):  
Chandreyee Maitra ◽  
Frank Haberl ◽  
Valentin D. Ivanov ◽  
Maria-Rosa L. Cioni ◽  
Jacco Th. van Loon
Keyword(s):  
Near Infrared ◽  
Spectral Characteristics ◽  
Selection Criterion ◽  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
Mid Infrared ◽  
X Ray ◽  
Stellar Density ◽  
Narrow Emission

Context. Finding active galactic nuclei (AGN) behind the Magellanic Clouds (MCs) is difficult because of the high stellar density in these fields. Although the first AGN behind the Small Magellanic Cloud (SMC) were reported in the 1980s, it is only recently that the number of AGN known behind the SMC has increased by several orders of magnitude. Aims. The mid-infrared colour selection technique has proven to be an efficient means of identifying AGN, especially obscured sources. The X-ray regime is complementary in this regard and we use XMM-Newton observations to support the identification of AGN behind the SMC. Methods. We present a catalogue of AGN behind the SMC by correlating an updated X-ray point-source catalogue from our XMM-Newton survey of the SMC with previously identified AGN from the literature as well as a list of candidates obtained from the ALLWISE mid-infrared colour-selection criterion. We studied the properties of the sample with respect to their redshifts, luminosities, and X-ray spectral characteristics. We also identified the near-infrared counterpart of the sources from the VISTA observations. Results. The redshift and luminosity distributions of the sample (where known) indicate that we detect sources ranging from nearby Seyfert galaxies to distant and obscured quasars. The X-ray hardness ratios are compatible with those typically expected for AGN, and the VISTA colours and variability are also consistent with AGN. A positive correlation was observed between the integrated X-ray flux (0.2–12 keV) and the ALLWISE and VISTA magnitudes. We further present a sample of new candidate AGN and candidates for obscured AGN. Together these make an interesting subset for further follow-up studies. An initial spectroscopic follow-up of 6 out of the 81 new candidates showed that all six sources are active galaxies, although two have narrow emission lines.

scholarly journals Galaxy And Mass Assembly (GAMA): assimilation of KiDS into the GAMA database

2020 ◽  
Vol 496 (3) ◽  
pp. 3235-3256 ◽  
Author(s):  
Sabine Bellstedt ◽  
Simon P Driver ◽  
Aaron S G Robotham ◽  
Luke J M Davies ◽  
Cameron R J Bogue ◽  
...  
Keyword(s):  
Near Infrared ◽  
Data Set ◽  
The Galaxy ◽  
Analysis Package ◽  
Selection For ◽  
Mass Assembly ◽  
A New Technique ◽  
Source Extraction ◽  
Homogeneous Data

ABSTRACT The Galaxy And Mass Assembly Survey (GAMA) covers five fields with highly complete spectroscopic coverage (>95 per cent) to intermediate depths (r < 19.8 or i < 19.0 mag), and collectively spans 250 deg2 of equatorial or southern sky. Four of the GAMA fields (G09, G12, G15, and G23) reside in the European Southern Observatory (ESO) VST KiDS and ESO VISTA VIKING survey footprints, which combined with our GALEX, WISE, and Herschel data provide deep uniform imaging in the $FUV/NUV/u/g/r/i/Z/Y/J/H/K_s/W1/W2/W3/W4/P100/P160/S250/S350/S500$ bands. Following the release of KiDS DR4, we describe the process by which we ingest the KiDS data into GAMA (replacing the SDSS data previously used for G09, G12, and G15), and redefine our core optical and near-infrared (NIR) catalogues to provide a complete and homogeneous data set. The source extraction and analysis is based on the new ProFound image analysis package, providing matched-segment photometry across all bands. The data are classified into stars, galaxies, artefacts, and ambiguous objects, and objects are linked to the GAMA spectroscopic target catalogue. Additionally, a new technique is employed utilizing ProFound to extract photometry in the unresolved MIR–FIR regime. The catalogues including the full FUV–FIR photometry are described and will be fully available as part of GAMA DR4. They are intended for both standalone science, selection for targeted follow-up with 4MOST, as well as an accompaniment to the upcoming and ongoing radio arrays now studying the GAMA 23h field.

Development of a NeuroNICU with a Broader Focus on All Newborns at Risk of Brain Injury: The First 2 Years

2018 ◽  
Vol 35 (12) ◽  
pp. 1197-1205 ◽  
Author(s):  
Elisabeth Yan ◽  
Kathi Randall ◽  
Valerie Chock ◽  
Alexis Davis ◽  
Cecelia Glennon ◽  
...  
Keyword(s):  
At Risk ◽  
Intensive Care ◽  
Brain Injury ◽  
Neonatal Intensive Care ◽  
Near Infrared ◽  
Neurologic Injury ◽  
Medical Diagnoses ◽  
Critically Ill Neonates ◽  
Video Eeg

Objective Many critically ill neonates have an existing brain injury or are at risk of neurologic injury. We developed a “NeuroNICU” (neurologic neonatal intensive care unit) to better provide neurologically focused intensive care. Study Design Demographic and clinical variables, services delivered, and patient outcomes were recorded in a prospective database for all neonates admitted to the NeuroNICU between April 23, 2013, and June 25, 2015. Results In total, 546 neonates were admitted to the NeuroNICU representing 32% of all NICU admissions. The most common admission diagnoses were congenital heart disease (30%), extreme prematurity (18%), seizures (10%), and hypoxic–ischemic encephalopathy (9%). Neuromonitoring was common, with near-infrared spectroscopy used in 69%, amplitude-integrated electroencephalography (EEG) in 45%, and continuous video EEG in 35%. Overall, 43% received neurology or neurosurgery consultation. Death prior to hospital discharge occurred in 11%. Among survivors, 87% were referred for developmental follow-up, and among those with a primary neurologic diagnosis 57% were referred for neurology or neurosurgical follow-up. Conclusion The NeuroNICU-admitted newborns with or at risk of brain injury comprise a high percentage of NICU volume; 38% had primary neurologic diagnoses, whereas 62% had medical diagnoses. We found many opportunities to provide brain focused intensive care, impacting a substantial proportion of newborns in our NICU.

scholarly journals The Swift Bulge Survey: optical and near-IR follow-up featuring a likely symbiotic X-ray binary and a focused wind CV

2020 ◽  
Vol 492 (3) ◽  
pp. 4344-4360 ◽  
Author(s):  
A W Shaw ◽  
C O Heinke ◽  
T J Maccarone ◽  
G R Sivakoff ◽  
J Strader ◽  
...  
Keyword(s):  
White Dwarf ◽  
Near Infrared ◽  
Substantial Contribution ◽  
Galactic Centre ◽  
First Year ◽  
X Ray ◽  
Giant Stars ◽  
Near Ir ◽  
Star Binary

ABSTRACT The nature of very faint X-ray transients (VFXTs) – transient X-ray sources that peak at luminosities $L_X\lesssim 10^{36} {\rm \, erg \, s^{-1}}$ – is poorly understood. The faint and often short-lived outbursts make characterizing VFXTs and their multiwavelength counterparts difficult. In 2017 April we initiated the Swift Bulge Survey, a shallow X-ray survey of ∼16 square degrees around the Galactic centre with the Neil Gehrels Swift Observatory. The survey has been designed to detect new and known VFXTs, with follow-up programmes arranged to study their multiwavelength counterparts. Here we detail the optical and near-infrared follow-up of four sources detected in the first year of the Swift Bulge Survey. The known neutron star binary IGR J17445-2747 has a K4III donor, indicating a potential symbiotic X-ray binary nature and the first such source to show X-ray bursts. We also find one nearby M-dwarf (1SXPS J174215.0-291453) and one system without a clear near-IR counterpart (Swift J175233.9-290952). Finally, 3XMM J174417.2-293944 has a subgiant donor, an 8.7 d orbital period, and a likely white dwarf accretor; we argue that this is the first detection of a white dwarf accreting from a gravitationally focused wind. A key finding of our follow-up campaign is that binaries containing (sub)giant stars may make a substantial contribution to the VFXT population.

scholarly journals Euclid preparation

2019 ◽  
Vol 631 ◽  
pp. A85 ◽  
Author(s):  
◽  
R. Barnett ◽  
S. J. Warren ◽  
D. J. Mortlock ◽  
J.-G. Cuby ◽  
...  
Keyword(s):  
Luminosity Function ◽  
Near Infrared ◽  
Selection Method ◽  
Early Type ◽  
Data Release ◽  
Rate Of Decline ◽  
Current Record

We provide predictions of the yield of 7 <  z <  9 quasars from the Euclid wide survey, updating the calculation presented in the Euclid Red Book in several ways. We account for revisions to the Euclid near-infrared filter wavelengths; we adopt steeper rates of decline of the quasar luminosity function (QLF; Φ) with redshift, Φ ∝ 10k(z − 6), k = −0.72, and a further steeper rate of decline, k = −0.92; we use better models of the contaminating populations (MLT dwarfs and compact early-type galaxies); and we make use of an improved Bayesian selection method, compared to the colour cuts used for the Red Book calculation, allowing the identification of fainter quasars, down to JAB ∼ 23. Quasars at z >  8 may be selected from Euclid OYJH photometry alone, but selection over the redshift interval 7 <  z <  8 is greatly improved by the addition of z-band data from, e.g., Pan-STARRS and LSST. We calculate predicted quasar yields for the assumed values of the rate of decline of the QLF beyond z = 6. If the decline of the QLF accelerates beyond z = 6, with k = −0.92, Euclid should nevertheless find over 100 quasars with 7.0 <  z <  7.5, and ∼25 quasars beyond the current record of z = 7.5, including ∼8 beyond z = 8.0. The first Euclid quasars at z >  7.5 should be found in the DR1 data release, expected in 2024. It will be possible to determine the bright-end slope of the QLF, 7 <  z <  8, M1450 <  −25, using 8 m class telescopes to confirm candidates, but follow-up with JWST or E-ELT will be required to measure the faint-end slope. Contamination of the candidate lists is predicted to be modest even at JAB ∼ 23. The precision with which k can be determined over 7 <  z <  8 depends on the value of k, but assuming k = −0.72 it can be measured to a 1σ uncertainty of 0.07.

scholarly journals Observing the high redshift Universe with Euclid

2017 ◽  
Vol 12 (S333) ◽  
pp. 238-241 ◽  
Author(s):  
René Laureijs
Keyword(s):  
Spatial Distribution ◽  
Rest Frame ◽  
Near Infrared ◽  
Target Identification ◽  
High Redshift ◽  
Starting Point ◽  
The Individual ◽  
High Redshift Universe ◽  
Identification And Characterization

AbstractEuclid enables the exploration of large sky areas with diffraction limited resolution in the optical and near-infrared, and is sensitive enough to detect targets at cosmological distances. This combination of capabilities gives Euclid a clear advantage over telescope facilities with larger apertures, both on ground and in space. The decision to mount in the NISP instrument one extra grism for the wavelength range 0.92-1.3 μm with a spectral resolution of R ≈260 makes possible a rest-frame UV survey of the early Universe in the redshift range 6.5 < z < 9.7. Euclid’s standard imaging with VIS in the 0.55-0.9 μm band and with NISP in the Y, J, H bands provide complementary photometry for further target identification and characterization. Euclid is a suitable facility to discover and map the spatial distribution of rare high-redshift targets and to collect statistically relevant samples, in particular of high redshift Lyα emitters and QSOs, which can be used as signposts of the cosmic structures. The Euclid surveys are also a starting point for deeper follow up observations of the individual high-z objects. We present the Euclid mission and discuss the detectability of high-z objects to probe the epoch of ionization.

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