Following the release of the call for LMT Science proposals (2018-S1), the LMT will begin a period of scientific observations lasting 6 months, from January 1st to June 30th 2018. This Science phase will consist of shared-risk observations using, for the first time, a 50m diameter primary active surface. In addition to the two instruments offered in previous observing seasons, the 3 mm band spectrograph Redshift Search Receiver (RSR) and the 1.1 mm continuum camera AzTEC, a new 16-pixel array 3 mm band spectrograph, SEQUOIA, will also be available. This LMT call for proposals (2018-S1) provides an opportunity to conduct scientific projects during the best winter and spring weather conditions for millimeter-wavelength observations, taking advantage of the higher angular resolution and sensitivity provided by the increased collecting area of the LMT.
All interested applicants for LMT Science observations should read the Announcement of Opportunity that contains information regarding guidelines for proposers, including the selection criteria for approved projects, and the composition of Scientific Project Teams.
This call for science projects is made with the understanding that all successful proposals and scheduled observations are considered as “shared-risk”. During this period of scientific observations the LMT user-community should be aware that the feasibility of the proposed observations may change due to differences in the instrument sensitivities and the efficiency of the telescope performance compared to those that are advertised in this call. Science observations may be rescheduled or cancelled according to the need for additional commissioning and engineering activities.
A new virtual LMT office (vLMT) has been implemented, based on a proposal submission system developed for the JCMT, and provides the tools to register, submit and monitor the status of all LMT proposals. Information regarding the proposal title, abstract, principal investigator and contact details will be entered directly into the online submission form. The list of astronomical targets and selection of instruments, and the scientific and technical justifications (including figures, tables and references) can also be entered directly into the online submission form or uploaded as separate documents.
The science observing proposals must be written in English. The scientific and technical proposal, if uploaded as two separate documents (PDFs), will be formatted on Letter-sized paper with a font size not smaller than 11 points, and all page margins must be at least 2cm. A total of five pages are available to present the scientific case: two pages to justify and describe the case, two pages for figures and tables, and a fifth page for references and a summary of the composition of the Scientific Project Team (see section below), including relevant experience, responsibilities, and the role of external (non-LMT partners) co-investigators. The technical justification should be uploaded in a separate single-page document. PDFs should not exceed 5Mb. If edited on-line, the scientific justification, references and description of the Scientific Project Team should not exceed the word limit of 2100 words. A maximum of 4 figures can be uploaded to the on-line system, each with a caption that does not exceed 250 words. If edited on-line, the technical justification should not exceed the word limit of 600 words, and a single figure (or table) may be uploaded to the on-line system with a caption not exceeding 250 words.
Membership of the Scientific Project Teams is open to individuals with affiliation at a Mexican research institution or at the Department of Astronomy at the University of Massachusetts and the Five College Astronomy Department. Scientific collaboration between the partners of the LMT project is strongly encouraged. Inclusion of additional external collaborators should be justified in the proposal and shown to offer an essential capability or unique resource to the project.
Proposals for LMT Science Observations must identify the full Scientific Project Team that will carry out the observational program. Each Scientific Project Team must demonstrate that it is self-sufficient, and contain team members that are familiar with the operation of the LMT, the preparation of the observing scripts, the use of the scientific instruments and the analysis of the data. It is strongly suggested that potential leaders of Scientific Project Teams contact the LMT Project Scientists, Miguel Chávez (email@example.com) and Min Yun (firstname.lastname@example.org), who will facilitate and coordinate the involvement of experienced LMT project personnel, and members of the instrument teams, within the individual Scientific Project Teams.
Depending on the assigned ranking of the proposal, following the scientific and technical peer-review, the Principal Investigator will be contacted before scheduling the scientific program on the LMT to prepare the selection of the target sources and the generation of the required observing scripts, and to organize the logistical support of the observations at the telescope. For safety reasons, it is mandatory that observers should be able and willing to drive the LMT vehicles and have a valid driver license.
A preliminary value of 85 microns r.m.s. is calculated for the total optical error budget, derived from measured deformations in the optics of the primary and secondary mirrors, plus estimates of the impact of environmental effects (wind loading and temperature gradients in the antenna support structure) on the primary surface. This estimated error of 85 microns r.m.s. is the default value used in the determination of the expected sensitivities of the Redshift Search Receiver, SEQUOIA and AzTEC during this Science opportunity with the LMT. Please note that the AzTEC camera will only illuminate the inner 32 m diameter of the active primary surface. Integration time and sensitivity calculators for the instruments are available in the virtual LMT office.
Given the experience from previous observing seasons, and taking into consideration the variable weather conditions, the telescope operational efficiency and the observing overheads, we anticipate ~600 hours of on-source integration time (~200hr optimal for observations at 1.1mm and 400hr at 3mm). The exact division of observing time between the instruments will depend on the scientific priority awarded to the individual projects.
Observations at 1.1mm (with AzTEC) are performed with opacities less or equal to 0.1, and at 3mm with 0.1 < tau < 0.3 (tau at 225GHz and measured towards the zenith). If the authors of a proposal that request AzTEC observations consider that the project can be successfully accomplished with higher opacities, this should be specified and justified in the Technical Justifications, including the suggested opacity limit. The same applies for RSR/SEQUOIA projects that may be successful with opacities > 0.3. If a RSR/SEQUOIA project requires observations with opacities < 0.1 (e.g. to detect sub-mK lines), this should also be specified and justified in the Technical Justification. A Technical Evaluation Committee will review these cases. If necessary, the PI will be contacted and asked to update the Technical Justification before the proposal is passed to the Scientific Evaluation Committee. It is important to note that all projects will be observed under the best possible weather conditions and atmospheric quality. This requested information, however, is crucial to allow a flexible scheduling and improve the LMT observing efficiency. Proposals with more relaxed weather and atmospheric quality specifications will always have a higher probability to be completed.
The primary telescope reflector is set with an active surface control system using photogrametry measurements over a wide elevation range. The active surface control system uses a model to correct the gravitational deformations of the primary reflector surface as the telescope moves in elevation. Over an elevation range of ~20 to 75 degrees the telescope has a measured constant and maximum aperture efficiency or gain.