scholarly journals Near-infrared Integral-Field Spectrograph (NIFS): An Instrument Proposed for Gemini

1999 ◽  
Vol 16 (3) ◽  
pp. 273-287 ◽  
Author(s):  
Peter J. McGregor ◽  
Peter Conroy ◽  
Gabe Bloxham ◽  
Jan van Harmelen

AbstractIn late 1998 the International Gemini Project Office identified a need for a low cost, near-infrared spectrograph to be commissioned on the Gemini South telescope on the shortest possible timescale. In response, the Research School of Astronomy and Astrophysics of the Australian National University proposed to design, construct, and commission a near-infrared, integral-field spectrograph on Gemini. The science drivers and novel design of the Near-infrared Integral-Field Spectrograph (NIFS) are described in this paper. NIFS will achieve significant economies in cost and schedule in several ways:• By addressing targeted science with high efficiency. NIFS will primarily target velocity measurements in galaxies to study the demographics of black holes in galactic nuclei and the evolution of structural properties in high redshift galaxies. However, NIFS will also be applied to a wide range of general astronomical topics, but these will not dictate the instrument design.• By adopting a largely fixed-format design. A 3·2″ × 3·2″ ‘stair-case’ integral field unit (IFU) will feed a near-infrared spectrograph with four fixed-angle gratings mounted on a single grating wheel. A single, fixed-format camera will form the spectral image on a 2048 × 2048 Rockwell HgCdTe HAWAII-2 array. Two-pixel spectral resolving powers of ∼5400 will be achieved with complete wavelength coverage in each of the J, H, and K photometric bands through 32 optimally sampled 0·1″ wide slitlets. The velocity resolution of ∼55 km s−1 will be sufficient to achieve the targeted science objectives, and will allow software rejection of OH airglow lines.• By packaging the NIFS instrument within a duplicate of the Near-Infrared Imager (NIRI) cryostat. The NIRI cryostat, On-Instrument Wavefront Sensor (OIWFS), detector focusing mechanism, control system, and EPICS software will all be duplicated with only minimal change. Construction of the duplicate NIRI cryostat, OIWFS, and control system will be done by the University of Hawaii.

2020 ◽  
Vol 498 (2) ◽  
pp. 1891-1904
Author(s):  
Mark L A Richardson ◽  
Laurence Routledge ◽  
Niranjan Thatte ◽  
Matthias Tecza ◽  
Ryan C W Houghton ◽  
...  

ABSTRACT We present simulated observations of gas kinematics in a galaxy formed in a 10 pc resolution cosmological simulation with the hydrodynamical +   N-body code ramses, using the new ramses2hsim pipeline with the simulated observing pipeline (hsim) for the Extremely Large Telescope High Angular Resolution Monolithic Optical and Near-infrared Integral field spectrograph (HARMONI IFS). We post-process the galaxy's gas kinematics and Hα line emission for each simulation cell, and integrate the emission to produce an extinction-corrected input cube. We then simulate observations of the input cube with HARMONI, for a range of exposure times, spatial sampling, and spectral resolution. We analyse the mock observations to recover galaxy properties such as its kinematics and compare with the known simulation values. We investigate the cause of biases between the ‘real’ and ‘observed’ kinematic values, demonstrating the sensitivity of the inferred rotation curve to knowledge of the instrument’s point spread function.


2013 ◽  
Vol 02 (01) ◽  
pp. 1350007 ◽  
Author(s):  
A. CALCINES ◽  
R. L. LÓPEZ ◽  
M. COLLADOS

This paper presents the proposal of a high resolution, integral field spectrograph that is currently being designed for the 4-meter aperture European Solar Telescope that will be located in the Canary Islands. This instrument is optimized to study the solar chromosphere and photosphere to allow the investigation of several phenomena concentrated within these two layers. It will be able to observe simultaneously a bidimensional field of view of 80 arcsec2 that is reorganized, using an integral field unit, into 8 long slits of 200 arcsec length by 0.05 arcsec width. It will have the capability to observe different layers of the Sun at the same time due to its multi-wavelength capability that allows the observation of 5 visible and 3 near-infrared wavelength intervals from 3900 to 23,000 Å, with a spectral resolution of about 300,000. The designed instrument is telecentric and presents an optical quality limited by diffraction.


2014 ◽  
Vol 635-637 ◽  
pp. 1155-1158
Author(s):  
Chao Ye ◽  
Ting You Wang ◽  
Ye Yuan

This paper presents a small ARM-based frequency control system, the voltage 220V/50Hz mains, rectified, filtered into DC, then reverse into adjustable frequency alternating current supplied to the motor used. Through software algorithms SPWM control signal generated by the microcontroller, the control signal sent through the intelligent power module, the realization of the DC inverter process. The design is simple, functional and meet the current frequency control system, modular, digital trends, has a waveform, small size, high efficiency, frequency wide range of features. Has good practical value and low cost.


2015 ◽  
Vol 11 (A29B) ◽  
pp. 764-767
Author(s):  
Johan Richard ◽  
Guillaume Mahler ◽  
Benjamin Clément ◽  
David Lagattuta ◽  
Vera Patriício ◽  
...  

AbstractStrong gravitational magnification in the core of lensing clusters allows to probe the faint-end of the galaxy luminosity function up to very high redshift. In particular, the Frontier Fields have allowed us to identify a large number of faint dropouts and constrain the Lyman-break luminosity function at z~5-7. I present here the results of an ongoing program with MUSE, a new integral field spectrograph on the Very Large Telescope having a large field of view (1 arcmin2), to confirm these candidate high redshift dropouts through Lyman-α emission and identify additional emitters with high equivalent width, fainter than the depth of the Frontier Fields Hubble images. Combined with similar deep exposures taken with MUSE in blank fields, this gives us the best opportunity to probe the Lyman-α luminosity function over a wide range in luminosity.


2012 ◽  
Author(s):  
Shinobu Ozaki ◽  
Yutaro Kitagawa ◽  
Kentaro Motohara ◽  
Masahiro Konishi ◽  
Hidenori Takahashi ◽  
...  

2015 ◽  
Vol 11 (A29B) ◽  
pp. 173-175
Author(s):  
B. W. Holwerda ◽  
W. C. Keel

AbstractInterstellar dust is still the dominant uncertainty in Astronomy, limiting precision in e.g., cosmological distance estimates and models of how light is re-processed within a galaxy. When a foreground galaxy serendipitously overlaps a more distant one, the latter backlights the dusty structures in the nearer foreground galaxy. Such an overlapping or occulting galaxy pair can be used to measure the distribution of dust in the closest galaxy with great accuracy. The STARSMOG program uses HST observation of occulting galaxy pairs to accurately map the distribution of dust in foreground galaxies in fine (<100 pc) detail. Furthermore, Integral Field Unit observations of such pairs will map the effective extinction curve in these occulting galaxies, disentangling the role of fine-scale geometry and grain composition on the path of light through a galaxy.The overlapping galaxy technique promises to deliver a clear understanding of the dust in galaxies: the dust geometry, a probability function of the amount of dimming as a function of galaxy type, its dependence on wavelength, and evolution of all these properties with cosmic time using distant, high-redshift pairs.


1995 ◽  
Vol 149 ◽  
pp. 298-299
Author(s):  
P. Martin ◽  
P.C. Pinet ◽  
R. Bacon ◽  
A. Rousset

AbstractHigh spectral and spatial resolution telescopic observations of the western hemisphere of Mars, using the integral field spectrograph TIGER at 0.8-1.1 µm, are described.


Author(s):  
Hasan H. Ali ◽  
Roger C. Fales ◽  
Noah D. Manring

This work introduces a new way to control hydraulic cylinder velocity using an inlet metering pump system to control the hydraulic flow entering the cylinder. The inlet metering system consists of a fixed displacement pump and an inlet metering valve that adjusts the hydraulic fluid flow entering the pump as required. The energy losses associated with flow metering in the system are reduced because the pressure drop across the inlet metering valve can be arbitrarily small. The fluid is supplied to the inlet metering valve at a fixed pressure using a charge pump. A velocity control system is designed using the inlet metering system as means to control the fluid flow to a hydraulic cylinder. In addition to the inlet metering system, the velocity control system designed in this work includes a four-way directional valve to set the fluid flow direction according to the desired direction of the hydraulic cylinder velocity. Open-loop and closed-loop proportional and proportional derivative (P and PD) controllers are designed. Designs with the goals of stability and performance of the system are studied so that a precise and smooth velocity control system for the hydraulic cylinder is achieved. In addition to potentially high efficiency of this system, there is potential for other benefits including low cost, fast response, and less complicated dynamics compared to other systems. The results presented in this work show that the inlet metering velocity control system can be designed so that the system is stable, there is zero overshoot and no oscillation.


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