NASA IRTF Fall 2018 News

Last updated 2 September 2018

2019A Call for Proposals

Proposal Deadline for Semester 2019A (February 1, 2019 to July 31, 2019) is Monday, October 1, 2018, 5PM Hawaii Standard time.

Available instruments are listed here. Remote observing is offered from any location with broadband Internet access for any project that utilizes IRTF facility instruments. Click here for more information.

IRTF Future Directions Workshop Update
We held a very successful workshop on the future of IRTF at the Biosphere 2 facility near Tucson on Feb 12-14. Input from the workshop will be used to explore possible future directions, to prepare white papers for input into the upcoming planetary and astrophysics decadal reviews, and to inform plans through and beyond the lease that ends in 2033 for operations of all the Maunakea telescopes. Workshop presentations are viewable here.

IRTF Data Reduction Update
A modified version of Spextool for the reduction of iSHELL spectra was made available by Mike Cushing and Bill Vacca. Please visit the IRTF data reduction pages for download and user instructions, as well as sample data and other useful resources. We have developed a version of xtellcor (named xtellcor_model) that uses atmospheric models instead of standard stars to remove telluric absorption lines in iSHELL spectra. We are currently testing the code on all iSHELL configurations. Optimization of the models to the observed spectra is typically required, and thus the method works best if at least a few telluric lines are separated from stellar features. At the same time we are testing a new method to correct the iSHELL echelle order curvature using flat fields rather than standard stars, as is currently the case. Observers should keep planning to take standard star spectra until the code and report are posted on the IRTF data reduction pages.Please contact Adwin Boogert for requests and questions about the reduction of IRTF data. We welcome software and calibration contributions by users as well.

Telescope Allocation Committee
The current TAC members for non-solar system proposals are: Máté Adamkovics (Clemson University), Katelyn Allers (Bucknell University), Harriet Dinerstein (University of Texas at Austin), and Lisa Prato (Lowell Observatory), and for solar system proposals are: Lori Feaga (University of Maryland), Driss Takir (USGS), Constantine Tsang (SwRI), and Bin Yang (ESO Chile). Charlie Conroy (Harvard-CfA), Serena Kim (University of Arizona), and Silvia Protopapa (University of Maryland) rotated off the TAC effective 2019A.

Help Keep Our Publications List Current
Please continue to acknowledge the IRTF in your publications following the instructions shown here. It is important that you include in your papers the name of the instrument used and the citation for the instrument, as this helps to ensure future funding of IRTF instruments.

IRTF Spectral Library
Users are encouraged to make use of the spectral library. The original library is available here. that consists of mostly solar-metallicity stars and the Extended IRTF library available here that extends the metallicity range. Contact John Rayner or Alexa Villaume for more details.

SpeX Prism Library
A library of more than 1000 prism spectra of low-mass stars and brown dwarfs is maintained by Adam Burgasser, and is available here.

NEO Spectral Survey
The MIT-IRTF Near-Earth Object spectral survey is underway, and many spectra are publicly available. See the side bar for more information or go to smass.mit.edu/minus.html.

IRTF News

Staffing:
Telescope operator Eric Volquardsen resigned in May to return to the mainland. We wish Eric all the best. A replacement is currently being recruited and should be in place by October. We are also recruiting an Observatory Supervisor to replace Imai Namahoe who is now Observatory Manager. An IRTF Mechanical Engineer is also being recruited to replace Morgan Bonnet.

IRTF Data Archive:
The IRTF Data archive is now open for use, and is being hosted by the NASA/IPAC Infrared Science Archive (IRSA). Raw data files taken with SpeX beginning Aug. 1, 2016, and with iSHELL beginning Feb. 1, 2017, are now publicly available via this site after a proprietary period of 18 months from the date of observation. As part of the archive process, the abstract field on the observing proposal form is being preserved and provided as metadata when data files are searched for or downloaded from the archive.

On Dec. 1, 2017 we announced that IRTF data for the years 2001 to 2016 would be made available on request following a proprietary period of 18 months, i.e. ‘legacy’ data will be available from June 1, 2019. It is planned that starting in June 2019, IRTF legacy data will be searchable via a web page, and data will be downloadable via a script generated by the webserver.

Further information can be viewed on the IRTF Data Release Policy page .

Dome Resurfacing:
Dome resurfacing with aluminum foil was successfully completed in July. Some smaller areas of the dome will be repainted over the next few months but this will not affect observing.

New Moveable Counterweights:
Two new moveable counterweights, each weighing 1000 kg, will be installed during semester 2019A, probably May. This will require a few days of telescope downtime but the time will be included as engineering time and so will not affect observers. With the addition of iSHELL it is currently not possible to balance the telescope for all combinations of facility and visitor instruments stowed on the multiple instrument mount (MIM), reducing scheduling flexibility. The new moveable counterweights will fix this.

Instrumentation Update

SpeX:
SpeX is a 0.7-5.3 micron medium-resolution spectrograph and imager. The 0.8 micron cut-on dichroic was replaced with a 0.7 micron dichroic during semester 2017A. This will increase the spectral wavelength grasp for optically guided solar system targets. Sub-arrays and movie mode are working again in the IR guider. Electronic observing logs are now available. For more information see the instrumentation page of the website or contact Mike Connelley.

MORIS:
MORIS is a 512x512 pixel Andor CCD camera mounted at the side-facing, dichroic-fed window of the SpeX cryostat (60"x60" field-of-view). Electronic observing logs are now available. For more information see the instrumentation page of the website or contact Bobby Bus.

iSHELL:
iSHELL is a 1.06 – 5.3 micron cross-dispersed echelle spectrograph (up to R=80,000) and imager. Wedged order-sorting filters are being procured to remove slight fringing in the spectra. We expect to install new filters covering the K-, L- and M-band modes in early 2019A, during which time iSHELL will be unavailable for one month. For semester 2019A we are again limiting the number of proposals requiring radial velocity precisions less than about 100 m/s since the results from commissioning runs are still being analyzed and the limiting precision is not yet know. Following the discovery that when operated at 80 K the silicon immersion grating is transparent down to 1.05 microns, a new observing mode (J0) has been added to cover the He I line at 1.08 microns. The data reduction tool for iSHELL is now available; it is part of the Spextool package. We have developed a version of xtellcor that uses atmospheric models instead of standard stars to remove telluric absorption lines in iSHELL spectra. For now we recommend that observers still take standard stars until they have compared both methods. For more details see: http://irtfweb.ifa.hawaii.edu/research/dr_resources. For more information see the instrumentation page of the website or contact John Rayner.

MIRSI/MOC:
MIRSI is a 5 – 20 micron camera and grism spectrograph. MIRSI was recently upgraded by IR Labs with a closed-cycle cooler to replace its liquid nitrogen and liquid helium cryostat. It is currently being further refurbished by IRTF with a new array controller and an optical channel similar to MORIS (MOC) with a 60"x60" field-of-view. For 2019A we are offering MIRSI and MOC in shared risk mode. A new chopping secondary mirror should also be available for use with MIRSI. Remote observing will be available with MIRSI and MOC. For more information see the instrumentation page of the website or contact Mike Connelley.