The ESO NTT (New Technology Telescope): The First Active Optics Telescope

Tarenghi, M.; Wilson, R. N.

doi:10.1117/12.960835

Cited by 19 publications

(11 citation statements)

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“…2). In order to study more deeply than 2MASS, we have carried out a NIR follow-up observation at ESO using NTT (Tarenghi and Wilson 1989) with the SOFI infrared camera during the nights of 2002 July 28th and 29th. SOFI has 1024 × 1024 HgCdTe pixels with a moderately large field of view (4.…”

Section: Nir Observation and Ntt/sofi Data Reductionmentioning

confidence: 99%

ChandraDeep X‐Ray Observation of a Typical Galactic Plane Region and Near‐Infrared Identification

Ebisawa

Tsujimoto

Paizis

et al. 2005

ApJ

104

159

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Using the Chandra Advanced CCD Imaging Spectrometer Imaging array (ACIS-I), we have carried out a deep hard X-ray observation of the Galactic plane region at (l, b) ≈ (28. • 5, 0. • 0), where no discrete X-ray source had been reported previously. We have detected 274 new point X-ray sources (4 σ confidence) as well as strong Galactic diffuse emission within two partially overlapping ACIS-I fields (∼ 250 arcmin 2 in total). The point source sensitivity was 1 code 662, NASA/GSFC, ∼ 3 × 10 −15 erg s −1 cm −2 in the hard X-ray band (2 -10 keV) and ∼ 2 × 10 −16 erg s −1 cm −2 in the soft band (0.5 -2 keV). Sum of all the detected point source fluxes accounts for only ∼ 10 % of the total X-ray flux in the field of view. Even hypothesizing a new population of much dimmer and numerous Galactic point sources, the total observed X-ray flux cannot be explained. Therefore, we conclude that X-ray emission from the Galactic plane has truly diffuse origin. Removing point sources brighter than ∼ 3 × 10 −15 erg s −1 cm −2 (2-10 keV), we have determined the Galactic diffuse X-ray flux as 6.5 ×10 −11 erg s −1 cm −2 deg −2 (2-10 keV). Only 26 point sources were detected both in the soft and hard bands, indicating that there are two distinct classes of the X-ray sources distinguished by the spectral hardness ratio. Surface number density of the hard sources is only slightly higher than that measured at the high Galactic latitude regions, indicating that majority of the hard sources are background AGNs. Following up the Chandra observation, we have performed a near-infrared (NIR) survey with SOFI at ESO/NTT. Almost all the soft X-ray sources have been identified in NIR and their spectral types are consistent with main-sequence stars, suggesting most of them are nearby X-ray active stars. On the other hand, only 22 % of the hard sources had NIR counterparts, which are presumably Galactic. From X-ray and NIR spectral study, they are most likely to be quiescent cataclysmic variables. Our observation suggests a population of 10 4 cataclysmic variables in the entire Galactic plane fainter than ∼ 2 × 10 33 erg s −1 . We have carried out a precise spectral study of the Galactic diffuse X-ray emission excluding the point sources. Confirming previous results, we have detected prominent emission lines from highly ionized heavy elements in the diffuse emission. In particular, central energy of the iron emission line was determined as 6.52 +0.08 −0.14 keV (90 % confidence), which is significantly lower than what is expected from a plasma in thermal equilibrium. The downward shift of the iron line center energy suggests non-equilibrium ionization states of the plasma, or presence of the non-thermal process to produce 6.4 keV fluorescent lines.

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Section: Nir Observation and Ntt/sofi Data Reductionmentioning

confidence: 99%

ChandraDeep X‐Ray Observation of a Typical Galactic Plane Region and Near‐Infrared Identification

Ebisawa

Tsujimoto

Paizis

et al. 2005

ApJ

104

159

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“…NTT/EFOSC2 instrument in imaging mode 62 . Observations started at 04:36:53 UT on 2019 January 16 with the g, r, i, z Gunn filters.…”

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confidence: 99%

Observation of inverse Compton emission from a long $γ$-ray burst

Acciari,

Ansoldi,

Antonelli

et al. 2020

Preprint

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“…These along with innovations in dome and building design and environmental control have reduced the Earth's atmospheric turbulence around the telescope and hence improved the seeing and thus the quality of the images taken with modern optical telescopes. [28,29]. The telescopes of sizes larger than 3-meter designed and built during last 2 decades are therefore using active support for both the primary and secondary mirrors.…”

Section: Impact Of Technological Development On Modern Optical and Nementioning

confidence: 99%

A Global Prospective of the Indian Optical and Near-Infrared Observational Facilities in the Field of Astronomy and Astrophysics: A Review

Sagar

2016

Proc. Natl. Acad. Sci., India, Sect. A Phys. Sci.

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A review of modernization and growth of ground based optical and near-infrared astrophysical observational facilities in the globe attributed to the recent technological developments in opto-mechanical, electronics and computer science areas is presented. Hubble Space Telescope (HST) and speckle and adaptive ground based imaging have obtained images better than 0.1 arc sec angular resolution bringing the celestial objects closer to us at least by a factor of 10 during the last two decades. From the light gathering point of view, building of large size (> 5meter aperture) ground based optical and near-infrared telescopes based on latest technology have become economical in recent years. Consequently, in the world, a few 8-10 meter size ground-based optical and near-infrared telescopes are being used for observations of the celestial objects, three 25-40 meter size are under design stage and making of a ~ 100 meter size telescope is under planning stage. In India, the largest sized optical and near-infrared telescope is the modern 3.6-meter located at Devasthal, Nainital. However, the existing Indian moderate size telescopes equipped with modern backend instruments have global importance due to their geographical location. Recently, the Government of India approved India's participation in the Thirty Meter Telescope (TMT) project.

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The ESO NTT (New Technology Telescope): The First Active Optics Telescope

Cited by 19 publications

References 0 publications

ChandraDeep X‐Ray Observation of a Typical Galactic Plane Region and Near‐Infrared Identification

ChandraDeep X‐Ray Observation of a Typical Galactic Plane Region and Near‐Infrared Identification

Observation of inverse Compton emission from a long $γ$-ray burst

A Global Prospective of the Indian Optical and Near-Infrared Observational Facilities in the Field of Astronomy and Astrophysics: A Review

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