scholarly journals Large angular scale fluctuations of near-infrared extragalactic background light based on the IRTS observations

2019 ◽  
Vol 71 (4) ◽  
Author(s):  
Min Gyu Kim ◽  
Toshio Matsumoto ◽  
Hyung Mok Lee ◽  
Woong-Seob Jeong ◽  
Kohji Tsumura ◽  
...  
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
High Redshift ◽  
Zodiacal Light ◽  
Extragalactic Background Light ◽  
Background Light ◽  
Normal Galaxies ◽  
Infrared Telescope ◽  
Angular Scale ◽  
Using Data

Abstract We measure the spatial fluctuations of the Near-Infrared Extragalactic Background Light (NIREBL) from 2° to 20° in angular scale at the 1.6 and $2.2\, \mu \mathrm{m}$ using data obtained with Near-Infrared Spectrometer (NIRS) on board the Infrared Telescope in Space (IRTS). The brightness of the NIREBL is estimated by subtracting foreground components such as zodiacal light, diffuse Galactic light, and integrated star light from the observed sky. The foreground components are estimated using well-established models and archive data. The NIREBL fluctuations for the 1.6 and $2.2\, \mu \mathrm{m}$ connect well toward the sub-degree scale measurements from previous studies. Overall, the fluctuations show a wide bump with a center at around 1° and the power decreases toward larger angular scales with nearly a single power-law spectrum (i.e., ${F[\sqrt{l(l+1)C_l/2\pi }]} \sim \theta ^{-1}]$, indicating that the large-scale power is dominated by the random spatial distribution of the sources. After examining several known sources, contributors such as normal galaxies, high-redshift objects, intra-halo light, and far-IR cosmic background, we conclude that the excess fluctuation at around the 1° scale cannot be explained by any of them.

scholarly journals Observations of the Near-Infrared Extragalactic Background Light

2001 ◽  
Vol 204 ◽  
pp. 87-100
Author(s):  
Toshio Matsumoto
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
High Redshift ◽  
Far Infrared ◽  
Zodiacal Light ◽  
Extragalactic Background Light ◽  
Background Light ◽  
Infrared Telescope ◽  
Total Energy Flux ◽  
Infrared Spectrometer

We searched for the near infrared extragalactic background light (IREBL) in data from the Near Infrared Spectrometer (NIRS) on the Infrared Telescope in Space (IRTS). After subtracting the contribution of faint stars and a modeled zodiacal component, a significant isotropic emission is detected whose in-band flux amounts to ~ 30 nWm−2sr−1. This brightness is consistent with upper limits of COBE/DIRBE, but is significantly brighter than the integrated light of faint galaxies. The star subtraction analyses from DIRBE data show essentially the same results apart from the uncertainty in the model of the zodiacal light. A significant fluctuation of the sky brightness was also detected. A 2-point correlation analysis indicates that the fluctuations have a characteristic spatial structure of 100 ~ 200 arcmin. This could be an indication of the large scale structure at high redshift. Combined with the far infrared and submillimeter EBL, the total energy flux amounts to 50 ~ 80 nWm−2sr−1 which is so bright that unknown energy sources at high redshifts are required.

scholarly journals Infrared Extragalactic Background Light

1990 ◽  
Vol 139 ◽  
pp. 317-326
Author(s):  
Toshio Matsumoto
Keyword(s):  
Near Infrared ◽  
Background Radiation ◽  
High Redshift ◽  
Dust Emission ◽  
Far Infrared ◽  
Cosmic Background Radiation ◽  
Infrared Region ◽  
Clear Correlation ◽  
Extragalactic Background Light ◽  
Background Light

Infrared extragalactic background light plays an important role in the study of the early history of the universe, especially as a probe to search for the primeval galaxies. In the near-infrared region, UV and visible light emitted from high redshift galaxies could be observable. Measurement of the sky fluctuation at 2.2 μm gives a very low upper limit. The rocket observation of the near-infrared diffuse emission reveals isotropic emission which is possibly ascribed to an extragalactic origin. The observed brightness and fluctuation are not consistent with the standard scenario of the primeval galaxies. In the far-infrared region, integrated light of dust emission of the distant galaxies forms another cosmic background radiation. IRAS and the Nagoya-Berkeley rocket experiment found a clear correlation between HI column density and far-infrared sky brightness; however, there remains an uncorrelated isotropic emission component. If we ascribe this emission to extragalactic origin, a fairly big evolution effect is required. In the submillimeter region, excess emission over the 2.74K blackbody spectrum was found, which requires the vast energy generation in the early universe.

Infrared Telescope in Space Observations of the Near‐Infrared Extragalactic Background Light

2005 ◽  
Vol 626 (1) ◽  
pp. 31-43 ◽  
Author(s):  
T. Matsumoto ◽  
S. Matsuura ◽  
H. Murakami ◽  
M. Tanaka ◽  
M. Freund ◽  
...  
Keyword(s):  
Near Infrared ◽  
Extragalactic Background Light ◽  
Background Light ◽  
Infrared Telescope ◽  
Space Observations

scholarly journals Fitting Zodiacal Models

2001 ◽  
Vol 204 ◽  
pp. 157-160 ◽  
Author(s):  
Edward L. Wright
Keyword(s):  
Solar System ◽  
Radiation Field ◽  
Measured Data ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Zodiacal Light ◽  
Extragalactic Background Light ◽  
Background Light

Models of the zodiacal light are necessary to convert measured data taken from low Earth orbit into the radiation field outside the Solar System. The uncertainty in these models dominates the overall uncertainty in determining the extragalactic background light for wavelengths λ < 100 μm.

scholarly journals Quasar Sightline and Galaxy Evolution (QSAGE) survey – I. The galaxy environment of O vi absorbers up to z = 1.4 around PKS 0232−04

2019 ◽  
Vol 486 (1) ◽  
pp. 21-41 ◽  
Author(s):  
R M Bielby ◽  
J P Stott ◽  
F Cullen ◽  
T M Tripp ◽  
J N Burchett ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
Near Infrared ◽  
Hubble Space Telescope ◽  
High Redshift ◽  
Star Forming ◽  
The Galaxy ◽  
Circumgalactic Medium ◽  
Galaxy Environment ◽  
Using Data ◽  
Galaxy Population

ABSTRACT We present the first results from a study of O vi absorption around galaxies at z &lt; 1.44 using data from a near-infrared grism spectroscopic Hubble Space Telescope Large Programme, the Quasar Sightline and Galaxy Evolution (QSAGE) survey. QSAGE is the first grism galaxy survey to focus on the circumgalactic medium at z ∼ 1, providing a blind survey of the galaxy population. The galaxy sample is H α flux limited (f(H α) &gt; 2 × 10−17 erg s−1 cm−2) at 0.68 &lt; z &lt; 1.44, corresponding to ≳0.2–0.8 M⊙ yr−1. In this first of 12 fields, we combine the galaxy data with high-resolution STIS and COS spectroscopy of the background quasar to study O vi in the circumgalactic medium. At z ∼ 1, we find O vi absorption systems up to b ∼ 350 kpc (∼4Rvir) from the nearest detected galaxy. Further, we find ${\sim }50{{\ \rm per\ cent}}$ of ≳1 M⊙ yr−1 star-forming galaxies within 2Rvir show no associated O vi absorption to a limit of at least N(O vi) = 1013.9 cm−2. That we detect O vi at such large distances from galaxies and that a significant fraction of star-forming galaxies show no detectable O vi absorption disfavours outflows from ongoing star formation as the primary medium traced by these absorbers. Instead, by combining our own low- and high-redshift data with existing samples, we find tentative evidence for many strong (N(O vi) &gt; 1014 cm−2) O vi absorption systems to be associated with M⋆ ∼ 109.5–10 M⊙ mass galaxies (Mhalo ∼ 1011.5–12 M⊙ dark matter haloes), and infer that they may be tracing predominantly collisionally ionized gas within the haloes of such galaxies.

scholarly journals Infrared Spectroscopy and Chemometric Applications for the Qualitative and Quantitative Investigation of Grapevine Organs

2021 ◽  
Vol 12 ◽  
Author(s):  
Elizma van Wyngaard ◽  
Erna Blancquaert ◽  
Hélène Nieuwoudt ◽  
Jose Luis Aleixandre-Tudo
Keyword(s):  
Infrared Spectroscopy ◽  
Large Scale ◽  
Data Science ◽  
Near Infrared ◽  
Critical Evaluation ◽  
Quantitative Investigation ◽  
Qualitative And Quantitative ◽  
Non Invasive ◽  
Agricultural Revolution ◽  
Using Data

The fourth agricultural revolution is leading us into a time of using data science as a tool to implement precision viticulture. Infrared spectroscopy provides the means for rapid and large-scale data collection to achieve this goal. The non-invasive applications of infrared spectroscopy in grapevines are still in its infancy, but recent studies have reported its feasibility. This review examines near infrared and mid infrared spectroscopy for the qualitative and quantitative investigation of intact grapevine organs. Qualitative applications, with the focus on using spectral data for categorization purposes, is discussed. The quantitative applications discussed in this review focuses on the methods associated with carbohydrates, nitrogen, and amino acids, using both invasive and non-invasive means of sample measurement. Few studies have investigated the use of infrared spectroscopy for the direct measurement of intact, fresh, and unfrozen grapevine organs such as berries or leaves, and these studies are examined in depth. The chemometric procedures associated with qualitative and quantitative infrared techniques are discussed, followed by the critical evaluation of the future prospects that could be expected in the field.

scholarly journals Large scale profiles of galaxies at z=0-2 studied by stacking the HSC SSP survey data

2016 ◽  
Vol 11 (S321) ◽  
pp. 318-320
Author(s):  
Mariko Kubo ◽  
Masami Ouchi ◽  
Takatoshi Shibuya
Keyword(s):  
Survey Data ◽  
Surface Brightness ◽  
Large Scale ◽  
High Redshift ◽  
Photometric Redshifts ◽  
Early Formation ◽  
The Galaxy ◽  
Strategic Program ◽  
Galaxy Populations ◽  
Using Data

AbstractWe are carrying out the study of the evolution of radial surface brightness profiles of galaxies from z = 0 to 2 by stacking analysis using data corrected by the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP). This will allow us to constrain the large scale average profiles of various galaxy populations at high redshift. From the stacking analysis of galaxies selected based on their photometric redshifts, we successfully detected the outer components of galaxies at z > 1 extending to at least ~80 kpc, which imply an early formation for the galaxy outskirts.

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