Long Range Plan 2020 / Plan à long terme 2020

By / par Pauline Barmby and / et Bryan Gaensler (LRP2020 Co-Chairs / co-présidents PLT2020)
(Cassiopeia – Spring / printemps 2020)

La version française suit

The LRP panel co-chairs attended the January AAS meeting to present a poster on LRP2020, hear about the current situation on Maunakea, and get updates on the current state of the US Astro2020 decadal survey. Results from Astro2020 are not expected to be released before January 2021. This has implications for Canada, since many of the projects being considered by LRP2020 are also being considered by Astro2020; after careful consideration we decided not to delay the LRP2020 report.

The panel has completed discussions of the projects, facilities and recommendations contained in the white papers, and decided on a set of priorities. Report-writing is underway. The panel met at NRC-Herzberg in February for an in-person writing retreat and continues to meet regularly online. We are still on schedule to present the draft recommendations in May at the CASCA AGM in Toronto.

The LRP webpage is a little more up-to-date than it was a few months ago and we hope to make the individual LRP2020 white papers and reports more easily accessible soon. The latest news on LRP2020 is available from the Slack workspace and our Twitter handle @LRP2020. The panel can be contacted at panel@lrp2020.groups.io and the co-chairs at chairs@lrp2020.groups.io.



Les coprésidents du panel PLT ont assisté à la réunion de janvier de l'AAS pour présenter une affiche sur PLT2020, entendre parler de la situation actuelle sur Maunakea et obtenir des mises à jour sur l'état actuel de l'enquête décennale américaine Astro2020. Les résultats d'Astro2020 ne devraient pas être publiés avant janvier 2021. Cela a des implications pour le Canada, car de nombreux projets envisagés par PLT2020 le sont également par Astro2020; après mûre réflexion, nous avons décidé de ne pas retarder le rapport PLT2020.

Le panel a achevé les discussions sur les projets, les installations et les recommandations contenues dans les livres blancs, et a décidé d'un ensemble de priorités. La rédaction du rapport est en cours. Le panel s'est réuni au CNRC-Herzberg en février pour une retraite d'écriture en personne et continue de se rencontrer régulièrement en ligne. Nous sommes toujours dans les délais pour présenter l'ébauche des recommandations en mai à l'AGA de la CASCA à Toronto.

La page Web du PLT est un peu plus à jour qu'il y a quelques mois et nous espérons rendre les livres blancs et rapports PLT2020 individuels plus facilement accessibles bientôt. Les dernières nouvelles sur PLT2020 sont disponibles sur l’espace de travail Slack et sur Twitter @LRP2020. Le panel peut être contacté à panel@lrp2020.groups.io et les co-présidents à chairs@lrp2020.groups.io.

CATAC Update on the Thirty Meter Telescope

By / par Michael Balogh (CATAC Chair)
(Cassiopeia – Winter / hivers 2019)

There has been no attempt to restart construction of the TMT since protestors blocked the Mauna Kea access road in mid-July. The protests, and the responses to them, have remained non-violent, as stakeholders work to find a solution to the conflict. Meanwhile, TMT opponents have been effectively disseminating their message, tapping into broader issues related to indigenous rights in Hawai’i and around the world. Parallels have been drawn with the findings of the Truth and Reconciliation committee here in Canada. This has mobilized some in Canada to express strong support for the view that the TMT project must do more to achieve the consent from Native Hawaiians before proceeding.

There is a long history of astronomy on Maunakea, including many stories of discovery and inclusiveness, but also a history of conflict that predates TMT. TMT itself has been part of the Canadian conversation since 2000, and the present site on Mauankea was selected (and supported by the Office of Hawaiian Affairs, a public agency responsible for improving the well-being of Native Hawaiians) ten years ago. This context is important, as are the efforts of the TMT project over the past decade to gain the consent and support of the Hawaiian population. To this end, CATAC prepared a document about the history and current status of the project, with several important references and links to factual information. To quote from that report:

All evidence is that the project followed procedures that were believed to be appropriate for obtaining consent from Hawaiians, and that construction halted in the face of protests. We see nothing shameful in trying to find a peaceful solution for a project that has been nearly twenty years in development, and that promises economic benefits to Hawaiians and scientific benefit to the world.

There appears to be a good understanding now, at least among most Canadian astronomers, University and political leaders, that Canada should not directly interfere in the process happening in Hawai’i. Mayor Harry Kim has been charged with negotiating a solution, and he released a report in late September titled The Heart of Aloha. While this short report is a good start, it is likely that additional, new ideas will be needed to resolve the conflict. We understand that there is still a lot of activity going on within the Hawaiian community to find a solution. Thus, we continue to wait to see if a path forward will emerge.

In the meantime, progress on obtaining two building permits at the alternative site in the Canary Islands continued, and both were in place by mid-November. Decisions on the next steps will be made by the TMT International Observatory (TIO) Members, who have been meeting regularly since August. The site at ORM presents its own significant challenges, scientifically, socially, financially and politically.

TMT and the LRP

CATAC provided a comprehensive report to LRP2020, which is meant to also serve many of the purposes of a white paper. TMT has been a topic of discussion at Town Halls across the country. At the moment there is uncertainty about the project, and much of this is likely to be resolved, one way or the other, well before the LRP report is published. Should a fundamental change (e.g. in site, scope, timescale etc) be announced, there will be a need for consultation and further input to the LRP process. CATAC is prepared to lead this process.

Instrumentation

Following discussion at the CASCA meeting in May, CATAC revised and finalized our recommendations for post-first light instrumentation. Those recommendations are summarized here for convenience:

  1. We recommend that Canadian SAC members support a transparent and effective instrumentation development plan, similar to the one presented by Luc Simard to the TMT SAC in November, 2010.
  2. Instrument teams require time and funding to develop ideas to the level that allows them to compete for significant external construction funds. We recommend that Canadian Board and SAC members emphasize the importance that the TIO provide funding for early design work (e.g. mini-studies) as well as for Conceptual Design Phases. Despite the budget challenges facing the project, this work must begin immediately if we are to have a competitive instrument suite on the telescope.
  3. We recommend that Canadians interested in the scientific or technical capabilities of an instrument contact other TMT partners and begin work on these ideas now, to the extent possible.
  4. The TMT Science Forums have proven to be fertile environments for building relationships between partners for instrument development. Forums have now been held in all partner countries except Canada. Canada should host the next TMT Science Forum.

Regarding the final recommendation, the SAC has expressed support for this proposal and it is expected that the next Science Forum will be held in Canada sometime in 2021.

The main new development is that the high-contrast, high-dispersion spectrograph MODHIS has been endorsed by the SAC as a first-light instrument, though its exact nature is still a topic of discussion. MODHIS will be effective for finding and characterizing massive exoplanets. Several Canadians are part of a CFI application that includes funding to participate in the development of this instrument.

Upcoming Events

The TMT Early Career Workshop will be held at HAA, May 26-June 1, 2020.

CATAC membership:
Michael Balogh (University of Waterloo), Chair, mbalogh@uwaterloo.ca
Bob Abraham (University of Toronto; TIO SAC)
Stefi Baum (University of Manitoba)
Laura Ferrarese (NRC)
David Lafrenière (Université de Montréal)
Harvey Richer (UBC)
Kristine Spekkens (Royal Military College of Canada)
Luc Simard (Director General of NRC-HAA, non-voting, ex-officio)
Don Brooks (Executive Director of ACURA, non-voting, ex-officio)
Rob Thacker (CASCA President, non-voting, ex-officio)
Kim Venn (TIO Governing Board, non-voting, ex-officio)
Stan Metchev (TIO SAC, non-voting, ex-officio)
Tim Davidge (TIO SAC Canadian co-chair; NRC, observer)
Greg Fahlman (NRC, observer)

CATAC Update on the Thirty Meter Telescope

By / par Michael Balogh (CATAC Chair)
(Cassiopeia – Autumn / l’automne 2019)

There has been no TMT construction activity since protestors blocked the access road on July 17. The situation remains peaceful, as described in our recent CASCA circular. We continue to welcome your feedback and questions. A good place for factual information about the work TMT has done to engage the Hawaiian community and more is the website www.maunakeaandtmt.org.

CATAC remains strongly supportive of the TMT, and of the activities the Project has undertaken over the past decade to consult with and engage the Hawaiian community. It has become increasingly clear in recent weeks that the most prominent voices heard during the first days following the anticipated restart of construction are not representative of most Hawaiians, including the Native population. There is significant support for TMT on the Big Island of Hawaii, and more and more people are coming forward to say so. Furthermore, many of the concerns expressed by the protestors have little to do with TMT itself, leaving hope that there is a way to address those concerns and build TMT at the same time.

As CATAC reported previously, the alternative site, in the Canary Islands, would allow TMT to realize most of its exciting potential. In particular, the site characteristics for adaptive optics in the near infrared are very competitive with those of Maunakea. However, the lower altitude and higher humidity of the ORM site severely compromise observations in the ultraviolet and mid-infrared. These wavelength regimes enable some compelling science cases, including the search for biosignatures on exoplanets. There is no doubt that Maunakea is superior to ORM for science observations, and for this reason we hope that, following some further work and negotiation, it will be possible to undertake TMT construction with broad Hawaiian support.

As we wait for these events to unfold, we are conscious of the potential additional delay to a project that is already five years behind schedule. The consequences of this should be considered deeply as we move into the process for LRP2020. TMT will hopefully have a long and productive lifetime – 40 years or more – and will shape many future generations of Canadian astronomers. It is CATAC’s opinion that the impact of this delay must be considered within this broader context: we must not risk or sacrifice the long-term benefits of having access to the best possible observatory for future Canadians.

It is important also to not lose focus on the long term development of this project, and with that in mind we remind you that the next TMT Science Forum will be November 4—6 2019, in Xiamen, China. This forum is a great opportunity to participate in, and influence, teams developing the future instrumentation suite for TMT. ACURA will again be providing some travel support for University-based researchers to attend this meeting. Requests can be directed to mbalogh@uwaterloo.ca.

We have proposed that the next Science Forum, sometime in 2020, be held in Canada, and this proposal has been welcomed by the Science Advisory Committee. Stay tuned for details.

CATAC membership:
Michael Balogh (University of Waterloo), Chair, mbalogh@uwaterloo.ca
Bob Abraham (University of Toronto; TIO SAC)
Stefi Baum (University of Manitoba)
Laura Ferrarese (NRC)
David Lafrenière (Université de Montréal)
Harvey Richer (UBC)
Kristine Spekkens (Royal Military College of Canada)
Luc Simard (Director General of NRC-HAA, non-voting, ex-officio)
Don Brooks (Executive Director of ACURA, non-voting, ex-officio)
Rob Thacker (CASCA President, non-voting, ex-officio)
Kim Venn (Science Governor for Canada on TIO Governing Board, non-voting, ex-officio)
Stan Metchev (TIO SAC, non-voting, ex-officio)
Tim Davidge (TIO SAC Canadian co-chair; NRC, observer)
Greg Fahlman (NRC, observer)

CATAC Update on the Thirty Meter Telescope

By / par Michael Balogh (CATAC Chair)
(Cassiopeia – Summer / été 2019)

CATAC has submitted a committee report to the LRP2020 panel. This report summarizes the recent history of Canada’s involvement with TMT, including issues related to construction and funding. It is a useful overview of our position in this important project, and is available both from the LRP panel report directory, and on our own webpage.

While the TMT International Observatory (TIO) now has the legal right to begin construction on Maunakea, there is still preparation work to be done. This includes applying for various permits which have expired and, importantly, coordinating with stakeholders including other Observatory Directors, the local police force, politicians, and residents. We expect that construction will restart sometime this northern summer.

In April CATAC published a revised draft of its recommendations on TMT instrumentation after first light. This was presented during the ACURA lunch session on Wed June 19, at this year’s annual CASCA meeting at McGill. A discussion was started at that session, but it is not too late to send us your feedback. CATAC needs to hear your ideas and ambitions so we can help ensure Canadian interests are well represented at the Board and SAC.

The next TMT Science Forum will be November 4-6 2019, in Xiamen, China. Please consider attending! ACURA will again be providing some travel support for University-based researchers to attend this meeting. Requests can be directed to mbalogh@uwaterloo.ca.

CATAC membership:
Michael Balogh (University of Waterloo), Chair, mbalogh@uwaterloo.ca
Bob Abraham (University of Toronto; TIO SAC)
Stefi Baum (University of Manitoba)
Laura Ferrarese (NRC)
David Lafrenière (Université de Montréal)
Harvey Richer (UBC)
Kristine Spekkens (Royal Military College of Canada)
Luc Simard (Director General of NRC-HAA, non-voting, ex-officio)
Don Brooks (Executive Director of ACURA, non-voting, ex-officio)
Rob Thacker (CASCA President, non-voting, ex-officio)
Kim Venn (Science Governor for Canada on TIO Governing Board, non-voting, ex-officio)
Stan Metchev (TIO SAC, non-voting, ex-officio)
Tim Davidge (TIO SAC Canadian co-chair; NRC, observer)
Greg Fahlman (NRC, observer)

CATAC Update on the Thirty Meter Telescope

By / par Michael Balogh (CATAC Chair)
(Cassiopeia – Spring / printemps 2019)

TMT Instrumentation Beyond First Light

Instrumentation for large telescopes takes a long time to develop, typically 7-10 years between start of conceptual design to first light. Work must start now if TMT is to realize its goal of introducing a new capability every two years after first light, and to remain competitive with ELT.

The Science Requirements Document (SRD) for the Thirty Meter Telescope (TMT) describes a range of capabilities (instruments and facility systems), and their requirements. The TMT Science Advisory Committee (SAC) last presented a preferred phasing of these capabilities in March 2011, and it is certainly time to revisit this. It is important that we in Canada give careful consideration to our own priorities so these can be clearly communicated to the SAC. US planning, for example, is being done in the context of possible access to both TMT and GMT, while Canadians and other partners will not have direct GMT access.

In late 2017 the SAC solicited, reviewed and ranked white papers from the TMT community. These rankings have not been made public, but the concepts under consideration are available here. This list represents a mild evolution of the original descriptions in the SRD.

A summary of the instruments under consideration for all three extremely large telescopes is given in the following table, with first light capabilities in boldface:

CATAC is preparing a review of these concepts and their phasing, with the aim of making recommendations that reflect Canada’s priorities. Your input is needed for this process! A draft for comment has been made available on our web page. Our March 26 CATAC Zoom meeting (3-4pm EDT) will be open to the public for discussion of this draft report. We encourage you to participate in that meeting, and/or send your feedback directly to mbalogh@uwaterloo.ca.

Wide Field Optical Spectrograph Progress

If you’d like to keep informed about the progress of WFOS, consider signing up to the mailing list here. The instrument team will be sending out occasional updates as the instrument’s specifications and science capabilities become increasingly defined.

Recent and Upcoming Meetings and Events

  • The next TMT Science Forum will be early November 2019, in China. The theme will likely be around multimessenger astronomy, and/or synergies with other facilities. Please consider attending! CATAC expects some funding will be available to help subsidize travel costs; stay tuned for a future announcement.
  • The CATAC meeting at 3pm EDT on March 26 will be open to CASCA members. We will discuss our draft recommendations on TMT instrumentation.
  • Extremely Big Eyes on the Early Universe, Sept 9-13, 2019 in Rome, Italy. This is the last of a three-part international conference series. Abstract submission deadline is April 15, and registration deadline is June 15.

CATAC Update on the Thirty Meter Telescope

By / par Michael Balogh (CATAC Chair)
(Cassiopeia – Winter / hivers 2018)

TMT Science Forum

The sixth TMT Science Forum was held in Pasadena, Dec 10-12. The agenda and participant list are available here. It was great to see so many Canadian researchers attending, and actively participating in the discussions. It was especially encouraging to see all the excellent science being done by our postdocs and graduate students, and their ambitions for more great things with TMT. Some of them also participated in the TMT Early Career Workshop the week before the Forum, where they were immersed in a start-to-finish instrument design experience.

A major focus of discussion was the US preparation for a preconstruction proposal to the NSF, largely to support instrumentation development, and preparation for the US Decadal survey Astro2020. Much of this work involves developing Key Science Programs, designed to make use of potential US access to both TMT and GMT. While this is a US-focused exercise, many of these Key Science Programs build on work that has already been done within the TMT community, by the International Science Definition Teams.

Compelling science cases were presented for several future instrument concepts, including multi-object NIR spectroscopy, high-contrast imaging and high-resolution spectroscopy. Discussion of the relative priorities of these concepts was an important agenda item for the SAC meeting that immediately followed the forum. Early in January, CATAC will be engaging with the Canadian community to develop a clear picture of where our priorities lie.

While this was the last Forum funded through the cooperative agreement with NSF that sparked the meetings, many people expressed the opinion that they should continue. While it is likely the next meeting will be held in China, I hope that we will consider hosting one in Canada perhaps the year after that.

Construction

The big news in the past months has been the positive ruling in both contested cases before the Hawai’i Supreme Court. First, in August, the Court ruled unanimously in favour of TMT on the issue of the sublease. Then, at the end of October, the Court delivered a 4-1 decision to uphold the Conservation District Use Permit issued to TMT by the Land Board. This is welcome news, that now gives TMT the legal right to restart construction. While it is expected that there will still be protests, the latest polls show strong support for TMT among Hawaiians. We are therefore hopeful that construction can begin soon, amid a welcoming environment in Hawai’i.

First Light Instrumentation

The SAC met in October to recommend a design choice for the Wide Field Optical Spectrograph, one of two first light instruments on the TMT. CATAC’s public report on the three designs under consideration was made available to SAC members. The SAC recommended that the project pursue the multi-slit imaging spectrograph design (Xchange), which was also the design preferred by CATAC. This concept will be the baseline for further development.

A conceptual design review of an adaptive secondary mirror (AM2) was held in October, and no show-stoppers were identified. However, there are risks associated with deploying an AM2 at first light, and it complicates commissioning. While an AM2 could have a big impact on future instruments, simplifying their design, it will not significantly affect WFOS or IRIS. Therefore, while there is interest in this being an early capability, it may not be necessary to push for it to be ready at first light.

Recent and Upcoming Meetings and Events

  • US-ELTP Splinter session at AAS, Seattle on Monday Jan 7, 2019
  • Conference, “Extremely Big Eyes on the Early Universe”, UCLA Jan 28-Feb 1, 2019

CATAC Update on the Thirty Meter Telescope

By / par Michael Balogh (CATAC Chair)
(Cassiopeia – Autumn / l’automne 2018)

Science Forum

Registration has now opened for the next TMT Science Forum, to be held December 10-12 in Pasadena, California. Please note that registration is free for students and members of the International Science Development Teams (ISDTs). In addition, ACURA has agreed to provide some travel support for University-based researchers who wish to attend this meeting, given its importance to the future success of TMT. To apply for this funding, please email mbalogh@uwaterloo.ca with a short description of your involvement in TMT, and your need for funding support.

Among other things, the Science Forum is an excellent opportunity for ISDT members to meet face to face. With Canada recently stepping up to join these ISDTs at an appropriate level, this is the time to take advantage of that membership to ensure your science interests are represented as TMT develops.

Instrumentation

The TMT Science Advisory Committee (SAC) is meeting Sept 12-13, and one of their main agenda items is to discuss progress with the Wide Field Optical Spectrograph (WFOS) design. The instrument team continues to work on advancing two possible designs: one using traditional slitmasks (Xchange) and another using optical fibers, over a wider field of view. At a recent, independent cost review, both instruments were found to significantly exceed the $50M cost cap when appropriate contingency is included. A subcommittee has been evaluating the scientific implications of proposed descope options for both designs, and will be reporting to the SAC at this meeting.

The other item before the SAC is a report from a subcommittee that has been considering white paper submissions for the next instrument to be constructed, after WFOS and IRIS. The SAC is in the process of reviewing and prioritizing the submissions, with a goal of identifying one or more studies for possible design funding.

Of likely relevance to future instrumentation discussion will be the Exoplanet Science Strategy report recently released by the U.S. National Academies of Science, Engineering, and Medicine (NASEM). The full report is available here. In particular, it recognizes the pivotal role that both TMT and GMT will play in the study of planet formation, and recommends that the National Science Foundation (NSF) invest in both the GMT and TMT and their exoplanet instrumentation to provide all-sky access to the U.S. community.

Funding and Construction Developments

In August, the Hawai’i Supreme Court ruled in favour of TMT regarding the case of the sublease. The issue at stake here was a possible requirement to conduct a contested case hearing for the granting of the sublease, as was done earlier this year for the Conservation District Use Permit (CDUP). The court ruled, unanimously, that a contested case hearing is not required for the sublease.

The remaining case before the Supreme Court is the appeal of the Land Board’s decision to award the CDUP itself. A decision is expected in the coming weeks, hopefully before the Board meeting in October. Coincidentally, the permitting process for the alternative site in the Canary Islands (ORM) is expected to conclude, following unanticipated bureaucratic delays.

As recently announced, the US community is now working under the leadership of NOAO to prepare a proposal for US participation in both TMT and GMT. If this is well received by the US Decadal planning process, it may pave the way for substantial (25%) NSF involvement in the project. A potential complication is that NSF participation will likely trigger the need for a federal Environmental Impact Statement (EIS). Depending on how this is staged, it could lead to further delays. No such EIS would likely be required for construction on ORM, La Palma. The Board is expected to make a site recommendation this October. CATAC will be revisiting our site selection report and recommendations from May 2017 to identify anything that might have changed or need more research, so that we can reaffirm or modify our recommendations as necessary. Continued input to CATAC on this important issue is still welcome.

CATAC Update on the Thirty Meter Telescope

By / par Michael Balogh, CATAC Chair
(Cassiopeia – Summer / été 2018)

Instrumentation

In April, CATAC submitted recommendations on the three design choices for the Wide Field Optical Spectrograph (WFOS), the result of a five month period of information gathering and community consultation. As one of only two first light instruments, the success of WFOS is critically important to the success of TMT. Our recommendation was that, while all three designs are exciting and capable of delivering excellent science, the Xchange design provides the best match to the top-level specifications. Moreover, the flexibility of this design, relative to the survey-oriented fibre design, is preferred. The final report is available on our web page.

Following this report, the instrument underwent a cost and risk review. At this review it was decided that the slicer design would not be pursued any further. Both the Xchange and fibre designs were found to significantly exceed the cost cap, and the instrument team has been charged with looking at how the designs can be altered to reduce cost. Neither design has a significant technical advantage or disadvantage; both have risks that will require some work.

The design work is expected to be completed by early July, to allow the SAC to make a recommendation by their July 26 meeting. In addition, a sub-committee of the TMT SAC has been formed to re-visit the science specifications that were originally defined for WFOS over a decade ago. The recommendations made by the sub-committee will also be discussed by the full SAC at that next meeting. The other TMT communities are undergoing a consultation process similar to the one held in Canada, and this information will be considered as well. There is still time for your voice to be heard, and if you have comments or concerns about WFOS please contact any CATAC member.

Work is also underway to select the third instrument to be built for TMT. Eight white papers have been submitted to the SAC, and these are currently being reviewed by a SAC subcommittee that includes representation from all the partners.

Science Forum

At the CASCA meeting in Victoria, it was announced that the next TMT Science Forum will be held December 10-12 in Pasadena, California. This will be an important meeting, likely coming after the pending legal decisions in Hawai’i have been resolved. We hope that many Canadians will consider attending this meeting. It is likely that some funding will be made available to help those who need it; an announcement will be made in the coming months.

Funding and Construction Developments

Gary Sanders (Project Manager) and Christophe Dumas (Observatory Scientist) summarized the current state of the project very well in their presentations at the CASCA AGM. There is lots of design and construction activity underway as we await the outcome of the permitting processes on both Maunakea and the alternate site in the Canary Islands.

As announced earlier this year, the US National Science Foundation (NSF), NOAO, TMT International Observatory and GMT Organization are working together to develop Key Science Programs that will be presented to the Decadal Review process in the US. If this is ranked highly by the Decadal Review Panel, NSF has communicated that they will be prepared to support a significant share (at least 25%) of both GMT and TMT, to provide access for the US community. This is a welcome development that provides a path to full construction. There remain issues to be resolved, including the timing of any funding and the Canadian share in the project. CATAC will continue to keep you informed as the situation develops; in the meantime, feel free to contact any CATAC member if you have questions or concerns.

CATAC Update on the Thirty Meter Telescope

By Michael Balogh, CATAC Chair
(Cassiopeia – Spring/printemps 2018)

The Wide Field Optical Spectrograph (WFOS) first-light instrument on TMT is expected to be a workhorse instrument that will appeal broadly to many in the Canadian community. This has proven to be a challenging instrument to design to requirements, and in the coming few weeks three different designs will be undergoing a technical and cost review process. CATAC has been working to understand these designs and gather input so we can present advice that reflects the needs of Canadian astronomers.

There are currently three compelling designs being considered:

  1. Fiber-WFOS: A fiber spectrograph that achieves a multiplicity of ~700 targets with R=5000 and full wavelength coverage, over a 79 square arcminute field of view. The challenge here is in achieving the necessary precision in sky subtraction and calibration, especially for faint objects at wavelengths redward of ~0.7 microns. There is no direct imaging mode, and the spectral resolution and angular sampling of each fiber is fixed. However, fibers can be bundled together to form multiple deployable IFUs. System throughput may be compromised in the near-UV and at wavelengths longward of ~0.9 microns.
  2. Slicer-WFOS: This design is an imaging spectrograph that uses image slicers to reduce the physical slit width to achieve R=5000, maintaining full spectral coverage from 310nm to 1000nm, but with a lower multiplicity of 33 over a 25 square arcminute field of view. The notional design for this option does not include imaging, although it likely could be added. The deployment of the slicer modules has been identified as a challenging operational issue.
  3. Xchange-WFOS: This is an imaging spectrograph with an object multiplicity of about 100 at resolution of R=5000, again over a 25 square arcminute field of view. Simultaneous coverage of the full wavelength range is not possible, but there is flexibility in using multiple gratings to achieve different resolutions. In terms of operational use, this design is most similar to multi-object spectrographs such as GMOS. Objects are placed on slits, using masks that are designed and cut for individual fields. Xchange-WFOS has an imaging capability. Like GMOS, there is also the option of adding an IFU.

All three designs have strong advantages and are exciting concepts; there are also technical and scientific trade-offs to be considered. The technical risks associated with all designs are being assessed by a committee that will advise the Scientific Advisory Committee (SAC) over the next couple of weeks. The SAC itself will meet April 9-10, 2018, and one of their tasks at that meeting will likely be to recommend proceeding with one or more of these three designs.

Scientifically, at a high level we might consider fiber-WFOS as best suited for “survey science”, where large samples of targets with a high density on the sky are gathered over large areas. On the other hand, the slicer- and Xchange-WFOS designs may be better suited for diagnostic spectroscopy: smaller samples of precision spectroscopy. But even this is an overly reductive description of capabilities.

CATAC needs to hear from you to provide appropriate advice. Some specific questions are:

  • How do you imagine you (or your immediate descendants!) using WFOS in 2028? Are the sample sizes, target densities, and S/N or resolution requirements better achievable with one design or another? Are there science programs where you feel that MOS with slits would be advantageous compared to fibers?
  • What spectral resolution or resolutions do you need for your science? If you could choose only one resolution, what would it be? Would it be acceptable to trade resolution against spectral coverage if the former were user-selectable?
  • What wavelength coverage is most important for your science? Is there a need for coverage with maximum throughput between 0.3 – 0.4 microns, or at wavelengths longer than 0.9 microns? Is there an advantage of simultaneous coverage, or is it sufficient to use multiple settings?
  • Is there a scientific need for seeing-limited (perhaps GLAO-assisted) imaging at visible – near-infrared wavelengths?

To help answer these questions we will be holding a public Webex meeting in advance of the April SAC meeting. Additional documentation describing the three instrument concepts will be made available, as possible, in the coming days via our website. We hope many of you will be able to attend, and/or send us your comments by email.

In other news, we await decision of the site selection. Disappointingly, the site permit for the ORM site in the Canary Islands has not yet been approved. There does not appear to be any fundamental obstacle to this permit, it is just taking longer than expected. In Hawai’i the political situation continues to change in a direction that is favourable to TMT construction. There are still two appeals in front of the Hawaii Supreme Court. One of them is being heard right now, and decisions on both are expected later this year. The good news is that the project continues to move forward in construction and design, with about 15 percent of the construction of components complete.

CATAC Update on the Thirty Meter Telescope

By Michael Balogh (CATAC Chair)
(Cassiopeia – Winter/hivers 2017)

The TMT Science Forum was held in Mysore, India on November 7-10. This is the first time one of these meetings took place in India, and it again proved a very effective venue for helping the partner communities become engaged with the project. The focus this year was on TMT instrumentation beyond first light. As announced in the last issue of e-Cass, TMT has issued a call for White Papers due March 21, 2018. These will be reviewed by the SAC, who will make recommendations for the next instrument(s) after first light. The Science Forum provided an opportunity to kick off some of the discussion. Talks are available here. There were also supporting workshops, held on November 6, for discussing three capabilities: a Planetary Science Imager, high resolution spectroscopy, and the first-light instrument WFOS.

At the last SAC meeting, some important updates were provided on both first light instruments for TMT: the infrared imaging spectrograph (IRIS) and the wide-field optical spectrograph (WFOS). In both cases there are decisions being made now, described below, that should be important to the Canadian community. CATAC is therefore following these developments closely.

IRIS successfully completed the second part of its Preliminary Design Review in September; reviews were very positive. The review focused on IRIS observing modes, its interaction with the AO system (NFIRAOS) and the data reduction system. As a result of the review, the IRIS science team is now discussing details of how observations will be taken, and how data will be reduced. NIRIS coupled with NFIRAOS is a very powerful, but complex, instrument that we expect to be of great interest to the Canadian community. If you are interested in knowing more, or would like to get involved, you are strongly encouraged to get in touch with one of the Canadian science team members: Tim Davidge, Pat Coté, or Christian Marois.

WFOS remains a very exciting and challenging instrument. Having earlier abandoned the original concept (MOBIE), the project is now currently considering two very different designs. One would use image slicers, robotically mounted onto masks, to enable multiobject spectroscopy up to high resolution (R~10,000) with narrow slits. The other is a fibre-based design that would allow patrol of the full field, but also bundling to make integral field units. Both designs have advantages and limitations. CATAC will be meeting with the PI of WFOS, Kevin Bundy, on Dec 19 to learn more about the risks and advantages offered by each approach, and the science input driving the specifications. We anticipate that early in 2018 we will be engaging you, the community, to ensure our Science team and SAC members are best able to represent Canadian interests at the time of this important decision.

In addition to these exciting developments, TMT has recently contracted a design study for a secondary adaptive mirror. Studies are underway to predict the improvement in performance as a function of wavelength, natural seeing and field of view. New simulation results will be presented at the next SAC meeting, in Feb 2018. Though this is unlikely to be a first light capability, it could be a priority for an upgrade not long after commissioning.

The political and legal situation in Hawai’i remains generally positive. Legal challenges remain. These are out of our hands and are being dealt with in the courts. The critical issue now is the time it takes to resolve these cases, but the Project remains optimistic that a site decision will be made in April 2018.

To help inform the community on the funding situation facing TMT, on Sept 26 CATAC hosted a public Webex with Ed Stone (Executive Director) and Gary Sanders (Project Manager). Over thirty CASCA members attended. We were presented with a frank and open description of the TMT budget and construction plans. One important takeaway from that meeting was how much impressive work is currently being done, by all partners, despite the delays. About 70% of the items are under contract right now, and roughly 10% of the project is complete. We also got a detailed description of how the project is costed, and how those costs are being revised. There is of course a significant funding gap, that is understood, and the plan submitted to the NSF included a set of options for staging the project. Further discussions with NSF, however, await a site decision.