Performance of the Hobby-Eberly Telescope and facility instruments

Hill, Gary J.; MacQueen, Phillip J.; Ramsey, Lawrence W.; Shetrone, Matthew

doi:10.1117/12.552439

Cited by 12 publications

(8 citation statements)

References 23 publications

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“…The relatively large size of the fibers projected on the sky means that the sensitivity limit is very insensitive to seeing degradation. Note that the median seeing for the site is about 1.0 arcseconds and the HET is delivering about 1.5 arcseconds median images, currently [37]. HET image quality will improve to close to site-limited with the advent of closed-loop control of the tracker.…”

Section: The Hobby-eberly Telescope and Virusmentioning

confidence: 98%

“…Model A of [38] shows that VIRUS with the above sensitivity limits would detect a surface density of LAEs of 5.5 per square arcminute, per ∆z=1, approximately constant with redshift over the 1.8 ¤ z ¤ 3.7 range of the observation. The HET has pioneered a design with a fixed spherical primary and a tracker to follow the motions of objects [37]. The design is particularly effective for surveys.…”

Section: The Hobby-eberly Telescope and Virusmentioning

confidence: 99%

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The Hobby-Eberly Telescope Dark Energy Experiment

Hill¹

2004

AIP Conference Proceedings

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We describe a project (HETDEX) to measure the evolution of dark energy out to z 4 with high precision. The galaxy power spectrum contains the baryonic oscillations seen in the CMB, and these features remain in the linear regime at high redshift. The separation of these peaks in the power spectrum is a standard ruler imprinted on both the angular and redshift space distribution of galaxies, providing direct constraints on the local Hubble constant H(z) and the angular diameter distance D A (z), both of which are related to the dark energy equation of state parameter w(z). We propose the use of Ly-α emitting galaxies as the tracer of the power spectrum, and describe the Visible IFU Replicable Ultra-cheap Spectrograph (VIRUS), capable of undertaking such a survey. VIRUS will be a very wide field integral field spectrograph of a new replicated design, consisting of more than a hundred individual spectrograph units. The VIRUS instrument mounted on a new wide field corrector on the Hobby-Eberly Telescope (HET) will allow 1 million Ly-α emitting galaxies to be mapped over 1.8 ¡ z ¡ 3.8 in 200 square degrees of sky, a volume 10 times that of the Sloan Digital Sky Survey (SDSS) in 100 nights of operation. This survey of large scale structure is sufficient to measure the power spectrum to 2-3% accuracy and constrain the positions of the baryonic acoustical peaks on the matter spectrum to ¢ 1%. This in turn provides sufficient accuracy on H(z) and D A (z) to challenge the level of dark energy constraint expected from the SNAP satellite at a fraction of the cost, while providing unique constraints at z£ 2. The baryonic acoustical peaks method is largely free of systematic biases and provides an independent test of results found by other methods. the constraint, allowing a wide range of possible evolution of the DE equation of state (e.g. [14]). Constraints involving SNe are now approaching the level where systematic uncertainties begin to dominate over random errors [13]. The current generation of experiments (ESSENCE (http://www.ctio.noao.edu/~wsne/), CFHT SNLS [15], and HST observations [2]) will reach the systematics dominated regime, and improved constraints will require the few

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Section: The Hobby-eberly Telescope and Virusmentioning

confidence: 98%

Section: The Hobby-eberly Telescope and Virusmentioning

confidence: 99%

The Hobby-Eberly Telescope Dark Energy Experiment

Hill¹

2004

AIP Conference Proceedings

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“…From the beginning, the Hobby-Eberly Telescope Marcario Low Resolution Spectrograph (LRS) 1 was designed with a near-IR extension in mind. 2 The refractive collimator and multi-object slitlets were built from near-IR compatible glasses and were optimized to work from 0.9 through 1.3 µm.…”

Section: Introductionmentioning

confidence: 99%

LRS-J: instrument design and characterization

et al. 2004

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LRS-J is a 142 mm f / 1 near infrared (J-Band) camera designed as a drop in replacement for the optical camera installed on the Hobby-Eberly Telescope (HET) multi-object low resolution spectrograph (LRS). The Hawaii-1RG (H1RG) based instrument is liquid nitrogen cooled, but it mates to the warm LRS making use of the existing longslit and multi-object (MOS) units as well as the existing optical collimator. LRS-J utilizes a molecular beam epitaxy (MBE) based Hawaii-1RG (H1RG) detector. The design is a fully cryogenic catadioptric Maksutov-type, with the detector at the internal focus. This configuration produces excellent images, but presents particular challenges in the mounting of the detector. This is the first time that such an arrangement has been used in an astronomical instrument with an infrared detector. By replacing the conventional optical grisms with two 170 mm diameter near-IR VPH grisms, LRS-J covers the 0.9-1.3 µm bandpass with R ~ 1750-2000.We present the opto-mechanical design of LRS-J including the thermally self-compensating corrector doublet mount, and 100 µm/turn cryogenic mirror adjusters, FEA optimized vacuum housing, and custom Dewar. We also characterize the electrical and thermal connections necessary to mount the detector head in this unusually small inverted arrangement.

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“…Early performance and commissioning difficulties are discussed by Hill et al [5] and Booth et al [6] but substantial efforts in the last two years to improve telescope systems and master the very complex operations in-herent in this telescope concept have brought the HET to routinely delivering site seeing limited images in the 1.3 arcsecond range. Current status and performance is presented by Booth et al [7] and Hill et al [8]. Current status and performance is presented by Booth et al [7] and Hill et al [8].…”

Section: Introduction To the Hobby-eberly Telescopementioning

confidence: 99%

Stellar Astrophysics on the Hobby-Eberly Telescope

Ramsey¹

2005

AIP Conference Proceedings

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We briefly describe the Hobby-Eberly Telescope (HET) and its present status and give several examples of successful stellar astrophysics programs. The HET was primarily driven by a science mission of conducting spectroscopic surveys. In addition the HET's unique design derives from considering that telescopes are largely used for exposure times of an hour or less at moderate zenith distances and modest image quality that is based on median site seeing which is consistent with a survey mission. We present results from planet searches, large radial velocity surveys, and Sloan Digital Sky Survey follow up programs in this context. The queue-scheduled nature of the HET makes it especially effective at synoptic programs that require a large aperture.1 Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the

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Performance of the Hobby-Eberly Telescope and facility instruments

Cited by 12 publications

References 23 publications

The Hobby-Eberly Telescope Dark Energy Experiment

The Hobby-Eberly Telescope Dark Energy Experiment

LRS-J: instrument design and characterization

Stellar Astrophysics on the Hobby-Eberly Telescope

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