scholarly journals The Southern Deep Near Infrared Survey (DENIS) a Prospect of PN Exploration

1993 ◽  
Vol 155 ◽  
pp. 39-39
Author(s):  
Stefan Kimeswenger ◽  
Christoph Kienel
Keyword(s):  
Surface Brightness ◽  
Near Infrared ◽  
Angular Resolution ◽  
Planetary Nebulae ◽  
Point Sources ◽  
Infrared Light ◽  
Sky Survey ◽  
Early Phases ◽  
Infrared Survey ◽  
Numerous Work

The near infrared light is important for the exploration of proto-planetary nebulae as well as for the planetary nebulae in early phases (Persi et. al. 1986, in Planetary and Proto-Planetary Nebulae: From IRAS to ISO, ed A. P. Martinez). Numerous work on the fluxes of the well known planetary nebulae was already done in the late 80's, but a sky survey will give a large sample of data to provide more detailed statistics.The present work presents an overview of the data on planetary nebulae expected from the European project of a deep near infrared survey of the southern sky (denis) (IAP and DESPA Paris, Heidelberg, Leiden, IAC Tenerife, Grenoble, Lyon, Frascati, Innsbruck, Vienna) in the I, J and K band with a limiting magnitude of 14.5 to 15 for point sources and 17 mag arcsec−1 for the surface brightness. The angular resolution for identification of non–point source objects will be about 5″.

scholarly journals Discovery of Infrared Stars in Globular Clusters in the Magellanic Clouds and Their Light Variations

1998 ◽  
Vol 11 (1) ◽  
pp. 395-395
Author(s):  
S. Nishida ◽  
T. Tanabé ◽  
S. Matsumoto ◽  
T. Onaka ◽  
Y. Nakada ◽  
...  
Keyword(s):  
Mass Loss ◽  
Globular Clusters ◽  
Main Sequence ◽  
Near Infrared ◽  
Magellanic Clouds ◽  
Infrared Light ◽  
Agb Stars ◽  
Dust Shells ◽  
Infrared Stars ◽  
Infrared Survey

A systematic near-infrared survey was made for globular clusters in the Magellanic Clouds. Two infrared stars were discovered in NGC419 (SMC) and NGC1783 (LMC). NGC419 and NGC1783 are well-studied rich globular clusters whose turn-off masses and ages are estimated MTO ~ 2.0 Mʘ and т ~1.2 Gyr for NGC419, and MT0 ~ 2.0 Mʘ and т ʘ 0.9 Gyr for NGC1783, respectively. The periods of the infrared light variations were determined to be 540 dfor NGC419IR1 and to be 480 d for NGC1783IR1, respectively. Comparison of the measurements with the period—if magnitude relation for carbon Miras in the LMC by Groenewegen and Whitelock(1996) revealed that the Kmagnitudes of the infrared stars were fainter by about 0.3 — 0.8 magnitude than those predicted by the P — K relation. This deviation can be explained if the infrared stars are surrounded by thick dust shells and are obscured even in the K band. The positions of NGC419IR1and NGC1783IR1 on the P — K diagram suggest that AGB stars with the main sequence masses of about 2 Mʘ start their heavy mass-loss when P ʘ 500 d.

scholarly journals Evidence of AGN-driven Outflows in Young Radio Quasars Selected from the Wide-field Infrared Survey Explorer

2013 ◽  
Vol 9 (S304) ◽  
pp. 347-348
Author(s):  
Minjin Kim ◽  
Luis C. Ho ◽  
Carol J. Lonsdale ◽  
Mark Lacy ◽  
Andrew W. Blain ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Emission Lines ◽  
Wide Field ◽  
Near Infrared Spectra ◽  
Sky Survey ◽  
Line Widths ◽  
Infrared Survey ◽  
Narrow Emission

AbstractWe present near-infrared spectra of young radio quasars selected by cross-correlating the Wide-field Infrared Survey Explorer (WISE) all-sky survey catalog with the radio catalog [Faint Images of the Radio Sky at Twenty cm (FIRST) and NRAO VLA Sky Survey (NVSS)]. The objects have typical redshifts of z ≈ 2 and [O III] luminosities of 107 erg s−1 comparable to those of luminous quasars. The observed flux ratios of narrow emission lines indicate that these objects appear to be powered by active galactic nuclei. The [O III] line is broad, with full width at half maximum ~1300 to 2100 km s−1, significantly larger than that of ordinary quasars. These large line widths might be explained by jet-induced outflows.

scholarly journals Bar Properties as a Function of Hubble Type

1996 ◽  
Vol 157 ◽  
pp. 23-29
Author(s):  
Debra Meloy Elmegreen
Keyword(s):  
Surface Brightness ◽  
Near Infrared ◽  
Spiral Galaxies ◽  
Infrared Light ◽  
Surface Photometry ◽  
Optical Surface ◽  
Barred Galaxies ◽  
Additional Information ◽  
Grand Design ◽  
Barred Spiral Galaxies

AbstractPrevious optical surface photometry of barred spiral galaxies revealed that there are two distinct types of bars: large bars tend to have a nearly constant surface brightness (”flat“ bar), while smaller bars tend to have a decreasing surface brightness with a scale length similar to the disk (”exponential“ bar). Statistically, flat bars tend to occur in early Hubble types and exponential bars in later types. Studies of resonances in spirals indicate that flat bars end inside corotation, while exponential bars end between the inner Lindblad and 4:1 resonances. Near-infrared (JHK) surface photometry of bars is presented in order to compare the stellar distributions and bar potentials in flat and exponential barred galaxies. The presence of isophotal twists in some galaxies provides additional information on resonances. The grand design and fiocculent optical structures in the two types of barred galaxies will be compared and contrasted with their near-infrared light distributions.

scholarly journals Observations of near-infrared H2 emission in Planetary Nebulae

1997 ◽  
Vol 180 ◽  
pp. 221-221 ◽  
Author(s):  
Harriet L. Dinerstein ◽  
James Crawford
Keyword(s):  
Thermal Shock ◽  
Planetary Nebula ◽  
Surface Brightness ◽  
Near Infrared ◽  
Planetary Nebulae ◽  
Resolving Power ◽  
Emission Mechanism ◽  
Recombination Line ◽  
Line Flux ◽  
K Band

We report the results of a near-infrared (mostly K-band) spectroscopic survey of planetary nebulae at McDonald Observatory during the period 1986-1993. These observations were made with a grating spectrometer based on a 1 × 32-element InSb array. Most of the K-band observations were taken with spectral resolving power R = λ/Δλ = 600 in order to resolve the v=1-0 S(1) 2.121 μm H2 line from the adjacent recombination line of He I at 2.113 μm. We also simultaneously measured the strengths of H I Br γ and He II 2.189 μm. The typical limiting line flux detected in our 3.8″ beam was 1-3 × 10–14 erg cm–2 s–1, corresponding to a surface brightness of 3 × 10–5 to 1 × 10–4 erg cm–2 s–1 ster–1. An early result of this study was the first conclusive proof that the UV-pumping or “fluorescence” mechanism, rather than thermal (shock) excitation, is responsible for the H2 emission in a planetary nebula, Hubble 12 (Dinerstein et al. 1988, ApJ, 327, L27). This was also one of the first demonstrated cases of UV-pumped H2 emission in any astronomical source, and Hubble 12 has become a template for the study of this emission mechanism.

scholarly journals A Near Infrared Survey of the LMC

1999 ◽  
Vol 186 ◽  
pp. 59-59
Author(s):  
Takehiko Wada ◽  
Munetaka Ueno ◽  
Toshikazu Ebisuzaki ◽  
Yosuke Ohno
Keyword(s):  
Near Infrared ◽  
New South ◽  
Black Body ◽  
Large Magellanic Cloud ◽  
Point Sources ◽  
Be Stars ◽  
Star Forming ◽  
South Wales ◽  
The University ◽  
Infrared Survey

We surveyed the central 3° × 6° region of the Large Magellanic Cloud (LMC) with angular resolution of 10″.0 at the J(1.25μm), H(1.65μm) and K′(2.15μm) bands. The observations were performed from Oct to Nov, 1994 at the Siding Spring Observatory. We used a 25 cm/F3.5 Newtonian telescope equipped with a 512×512 PtSi-Camera (Ueno et al. 1992). The plate scale was 4.″6 × 6.″0/pixel and the total field of view was 40.′2 × 52.′3. The system was attached onto the Automated Patrol Telescope of the University of New South Wales. The limiting magnitudes of the survey were 13.6, 11.9, and 10.0 magnitude (3σ) at the J, H, and K′ bands, respectively. The positions and the J, H, and K′ magnitudes were derived for 1599 point sources whose S/N ratio were more than four at the K′-band. The dominant components of the sources are red super giants (RSG), luminous M-type giants and AGB stars in the LMC. The distributions of RSG, luminous giants and CO line flux are spatially different from each other. This supports the idea that the position of the active star forming region has changed during the past 108 years. The detected sources are cross-identified with the IRAS Point Source Catalog. Sixty-two of 680 IRAS sources in the region spatially coincide with the detected sources and the spectrum energy distributions from 1.25μm to 100μm were derived for these 62 sources. Half of them are well described by a black body spectrum, while the others show a flat or redder spectrum. These latter sources are supposed to be stars with dust envelopes.

scholarly journals The Two Micron All-Sky Survey: Removing the Infrared Foreground

2001 ◽  
Vol 204 ◽  
pp. 197-207
Author(s):  
John E. Gizis ◽  
Michael F. Skrutskie
Keyword(s):  
Near Infrared ◽  
High Reliability ◽  
Sky Survey ◽  
Data Release ◽  
Infrared Background ◽  
Infrared Survey

We introduce the properties of the Two Micron All-Sky Survey (2MASS) for IAU Symposium 204. 2MASS is a near-infrared survey of the entire sky characterized by high reliability and completeness. Catalogs and images for 47% of the sky are now available online. This data release has been used by Wright (2000) and Cambrésy et al. (2000) to subtract the stellar foreground at 1.25 and 2.2 microns from COBE DIRBE data, revealing the cosmological near-infrared background.

scholarly journals The Diffuse Near- and Mid-Infrared Emission from the Galaxy

2001 ◽  
Vol 204 ◽  
pp. 35-46
Author(s):  
Martin Cohen
Keyword(s):  
Point Source ◽  
Surface Brightness ◽  
Near Infrared ◽  
Infrared Emission ◽  
Point Sources ◽  
Mid Infrared ◽  
Deep Point ◽  
Model Predictions ◽  
The Galaxy ◽  
Fundamental Stellar Parameters

Recognition of an isotropic cosmic near-infrared (NIR) and mid-infrared (MIR) background involves the removal of the zodiacal foreground (both scattered and reradiated), of the truly diffuse Galactic foreground (dominated by fluorescent bands of polcyclic aromatic hydrocarbons), and of resolved and unresolved Galactic point sources. I discuss model simulations of the near- and mid-infrared point source sky from which one can assess its particular contribution to the diffuse Galactic infrared foreground. I will also indicate the transitional stage which characterizes our knowledge of fundamental stellar parameters that are essential inputs to any such models. Using the latest version of the SKY model (Wainscoat et al. 1992; Cohen 1993; Cohen 1994; Cohen et al. 1994; Cohen 1995; Ruphy et al. 1997), I will demonstrate matches to deep point source counts for a variety of passbands and galactic latitudes, and will try to quantify the uncertainties achievable in model predictions of the integrated surface brightness due to the smearing of all these foreground point sources.

scholarly journals Near-infrared scattering as a dust diagnostic

2018 ◽  
Vol 614 ◽  
pp. A95 ◽  
Author(s):  
Mika Saajasto ◽  
Mika Juvela ◽  
Johanna Malinen
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Radiation Field ◽  
Molecular Cloud ◽  
Surface Brightness ◽  
Near Infrared ◽  
Infrared Light ◽  
Mid Infrared ◽  
Cloud Models ◽  
Average Grain Size

Context. Regarding the evolution of dust grains from diffuse regions of space to dense molecular cloud cores, many questions remain open. Scattering at near-infrared wavelengths, or “cloudshine”, can provide information on cloud structure, dust properties, and the radiation field that is complementary to mid-infrared “coreshine” and observations of dust emission at longer wavelengths. Aims. We examine the possibility of using near-infrared scattering to constrain the local radiation field and the dust properties, the scattering and absorption efficiency, the size distribution of the grains, and the maximum grain size. Methods. We use radiative transfer modelling to examine the constraints provided by the J, H, and K bands in combination with mid-infrared surface brightness at 3.6 μm. We use spherical one-dimensional and elliptical three-dimensional cloud models to study the observable effects of different grain size distributions with varying absorption and scattering properties. As an example, we analyse observations of a molecular cloud in Taurus, TMC-1N. Results. The observed surface brightness ratios of the bands change when the dust properties are changed. However, even a change of ±10% in the surface brightness of one band changes the estimated power-law exponent of the size distribution γ by up to ~30% and the estimated strength of the radiation field KISRF by up to ~60%. The maximum grain size Amax and γ are always strongly anti-correlated. For example, overestimating the surface brightness by 10% changes the estimated radiation field strength by ~20% and the exponent of the size distribution by ~15%. The analysis of our synthetic observations indicates that the relative uncertainty of the parameter distributions are on average Amax, γ ~ 25%, and the deviation between the estimated and correct values ΔQ < 15%. For the TMC-1N observations, a maximum grain size Amax > 1.5μm and a size distribution with γ > 4.0 have high probability. The mass weighted average grain size is ⟨am⟩ = 0.113μm. Conclusions. We show that scattered infrared light can be used to derive meaningful limits for the dust parameters. However, errors in the surface brightness data can result in considerable uncertainties on the derived parameters.

scholarly journals Peculiar X-ray features in bright early-type galaxies

2000 ◽  
Vol 174 ◽  
pp. 197-201
Author(s):  
Ginevra Trinchieri
Keyword(s):  
High Resolution ◽  
Surface Brightness ◽  
Point Sources ◽  
Early Type ◽  
X Ray ◽  
Sky Survey ◽  
The Absolute ◽  
Very High ◽  
Extended Emission

IC 1262 and NGC 6159 have been selected for high resolution observations because their X-ray luminosity observed in the ROSAT All Sky Survey (Voges 1992) was higher than that observed from other normal, early type galaxies. The HRI observations confirm both the identification of the X-ray sources with the two galaxies (see Fig. 1; point sources in the field, clearly associated with optical counterparts, further ensure that the absolute pointing is correct), and the very high luminosities. Moreover, they indicate very extended emission, out to ≥ 7′ and ≥ 4′ radius (≥ 400 and ≥ 220 kpc at the galaxies’ distances), respectively, with a relatively regular morphology (although not azimuthally symmetric at large radii), and a smoothly decreasing surface brightness profile. At the center of IC 1262, however, several peculiar features are present (see Fig. 3 and later discussion).

scholarly journals Four New Evolved Planetary Nebulae

1993 ◽  
Vol 155 ◽  
pp. 34-34
Author(s):  
S. Tamura ◽  
R. Weinberger
Keyword(s):  
Planetary Nebula ◽  
Surface Brightness ◽  
Planetary Nebulae ◽  
Advanced Stage ◽  
Spectroscopic Observations ◽  
Sky Survey ◽  
Low Surface Brightness

While examining Palomar Observatory Sky Survey prints for various purposes, we came upon a number of hitherto uncatalogued nebulous objects, all of them of low surface brightness. Four of them are considered by us as new planetary nebula candidates due to their morphology. For the brightest one of them, spectroscopic observations were carried out with the Cassegrain spectrograph attached to the 74-inch telescope of the Okayama Astrophysical Observatory: this object (1 = 65.49°, b = +3.18°) is clearly confirmed as a planetary nebula and obviously is in an advanced stage in its evolution; in Fig. 1, a spectrum of it is shown.

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