Herschel-HIFI news

From Sylvie Beaulieu, Herschel-HIFI Instrument Support Scientist

Herschel feature story

The current (September 2014) Herschel Feature Story on the Herschel website is Young Sun’s Violent History Solves Meteorite Mystery. Herschel_spacecraft_artist410

Continued support for using Herschel Science Archive data

On the 29th of October 2013, the last proprietary science observation was released into public domain through the Herschel Science Archive. This represents an excellent opportunity for additional astronomical discoveries for the larger Canadian astronomical community. The University of Waterloo Herschel-HIFI Group remains dedicated to help you achieve your scientific goals.

Herschel Interactive Processing Environment (HIPE)

HIPE 12.1 is the current released version. Please visit What’s New in HIPE for the latest changes in this release. The task hebCorrection can help mitigate the electric standing waves in HEB (bands 6 and 7). Detailed instructions on how to use the task are in the HIFI Data Reduction Guide. Additional information can be found in the HIFI Instrument and Calibration webpage, under Outstanding Calibration Issues.

Warning: a major bug in gain fitting was discovered in the doDeconvolution task. When running the task, this feature should not be used. A revamp of the task (and its documentation) is underway for HIPE 13. Stay tune…

At last! New HIFI beam release

The HIFI team has released a revised version of their beam, involving in particular updates to the coupling efficiencies and Half-Power-Beam-Width, and the delivery of detailed 2D beam models in each HIFI band. A new section of the HIFI calibration page has been created to this effect and Users are invited to carefully read the release notes prepared with these updates. In particular, we want to emphasise that the newly derived aperture and main beam efficiencies have dropped by up to 10% and 20% respectively, leading to equivalent increase of the converted fluxes or main beam temperatures. If you need any additional information in that respect please contact the Helpdesk.

Conferences, workshops and webinars related to Herschel

NRC Herzberg News

By Dennis Crabtree, Director Dominion Astrophysical Observatory (acting) & Optical Astronomy Program Leader (acting)
with contributions from Alan McConnachie, James Hesser, Gary Hovey, Gordon Lacy, Kei Szeto

These reports will appear in each issue of E-Cass with the goal of informing the Canadian astronomical community on the activities at NRC Herzberg.

Feedback is welcome from community members about how NRC Herzberg is doing in fulfilling our mandate to “operate and administer any astronomical observatories established or maintained by the Government of Canada” (NRC Act).

Cyber Intrusion at NRC

On 29 July, NRC announced that it had detected and confirmed a cyber intrusion on its IT infrastructure. NRC took steps to protect its information and the information of its clients and stakeholders by isolating its information holdings and shutting down servers including several at NRC Herzberg, that contained sensitive information.

We were able to implement some important workarounds to keep the majority of our services running. NRC Herzberg expects to be able to resume normal activities by the middle of October.

Return of Public Outreach to DAO

Efforts initiated in summer 2013 by community groups bore fruit. Groups distressed by the closure of the public outreach program operated at the Centre of the Universe facility on Observatory Hill worked with NRC to restore some outreach activities for summer 2014. This was spurred by on-line petitions organized by Don Moffatt (an interpreter at DAO in the 1990s) and by MLA Lana Popham, in whose riding the DAO is located. Last November MLA Popham organized at DAO a critical meeting of community representatives, in which NRC VP Dan Wayner participated with Greg Fahlman and Jim Hesser. This created the atmosphere for productive discussions with Observatory and NRC management that ultimately led to two, highly successful, pilot projects to re-introduce astronomy-themed education and public outreach during summer 2014.

NRC facilitated access for the University of Victoria’s Science Venture (SV) program to the Centre of the Universe building for weekly astronomy and space science camps for students in grades 3-5 (5 sessions) and 6-8 (3 sessions) in July and August. These camps were in addition to SV’s regular summer programming on campus, and represented a bold initiative to set up a pilot program off campus. 144 of the 185 available spaces (78%) were filled (with girls being 24% of the total). SV’s program director Melisa Yestrau observes, “We had incredible feedback from parents and campers about the venue and programming.”

RASC members setting up their personal telescopes for public view on the last public observing session for 2014 (6 September). (Photo: J. Hesser)

RASC members setting up their personal telescopes for public view on the last public observing session for 2014 (6 September). (Photo: J. Hesser)

Similarly, NRC entered a pilot agreement with the Victoria Centre of the Royal Astronomical Society of Canada to take responsibility for public viewing on seven Saturday nights July through early September. RASC exercised full responsibility for programming and interacting with the public, while NRC provided Commissionaires for overall site security and access control, an experienced operator for the Plaskett Telescope, and trained four RASC members to operate the Plaskett safely. RASC volunteers operated their personal telescopes for night viewing, as well as provided all the tours in the Plaskett dome. 2202 members of the public participated, with reactions being very enthusiastic. Don Moffatt’s and Lana Popham’s continued strong support was evident through their participation throughout the summer. In addition, Don arranged for flautist Martina Peladeau and guitarist Ian Bezpalko each to provide lovely music in the Plaskett dome at the beginning of more than half the evenings.

We’ll be gathering the lessons learned and looking at what they portend for 2015, but enthusiasm among the two community groups to continue upon their 2014 successes already seems apparent.

15m Dish Verification Antenna (DVA1)

NRC’s SKA Dish Verification Antenna 1

NRC’s SKA Dish Verification Antenna 1

The NRC has begun testing its 15m Dish Verification Antenna (DVA1) a novel prototype for the Square Kilometre Array (SKA). The antenna is optimised for mass production, low cost and high performance – key requirements for SKA antennas. The antenna is an offset Gregorian design developed in collaboration with the US Technology Development Program (US-TDP). A key innovation is the rim supported primary and secondary reflectors that are a carbon fibre composite monocoques design developed at the NRC’s Dominion Radio Astrophysical Observatory, near Penticton. The reflectors are made in a single piece on a precision mold using the vacuum infusion process yielding a precise reflector that can be mass produced with low overall cost.

The primary and secondary have been measured and are within 0.89 mm and 0.2 mm of ideal. Using better molds the NRC team has demonstrated that these errors can be halved yielding reflectors that operate to 20+ GHz and are very stable over temperature, wind and gravity loads compared to conventional approaches.

First Light on the Sun @ 11.75 to 13.25 GHz

First Light on the Sun @ 11.75 to 13.25 GHz

Testing of the DVA1 is well underway. First light at Ku band on the Sun was achieved at the beginning of August, with holography, pointing and antenna temperature measurements to be completed this fall.

Maunakea Spectroscopic Explorer (MSE)

The Maunakea Spectroscopic Explorer (MSE, formerly ngCFHT) continues to make important progress as it begins a Construction Proposal Phase that will last approximately 3.5 years, and which is led by the newly formed Project Office. Important progress in the last few months includes:

  • the formation of a Science Team, currently with over 60 members including 10 members from Canada, as well as members from Australia, China, France, Hawaii, India, Japan, mainland USA and elsewhere. August saw the start of science team activities, with White Papers solicited to provide new input to the science development.
  • the formation of a Science Executive with Contact Scientists from Australia (Andrew Hopkins), Canada (Michael Balogh), France (Nicolas Martin), India (Gajendra Pandey), with other partner countries soon to have representation. This group provides leadership of the science team in collaboration with the Project Scientist (Alan McConnachie).
  • the ranking of MSE in the top priority bracket for development in the first draft of France’s new 5-year Prospective (roughly equivalent to their LRP). MSE and CFHT remain engaged in the ongoing development of the Prospective.
  • establishment of much of the basic infrastructure required to operate the Project Office, with headquarters in Waimea.
  • exploration of permitting issues and options for MSE consistent with the Maunakea Comprehensive Management Plan.
  • visits and important discussions with our colleagues in China, the Republic of Korea, Taiwan and Japan regarding partnership engagement in the future development of CFHT and MSE, and a planned visit to India this Fall.

Please do not hesitate to contact the following for any questions relating to MSE:

  • MSE Project Scientist (Alan McConnachie; mcconnachie@mse.cfht.hawaii.edu)
  • Project Manager (Rick Murowinski; murowinski@mse.cfht.hawaii.edu)
  • CFHT Executive Director (Doug Simons; simons@cfht.hawaii.edu)

Visit the MSE website at mse.cfht.hawaii.edu for more information and recent news.

NFIRAOS

For the past few months, the NFIRAOS team has been working diligently to engage Canadian industry to progress the NFIRAOS’ opto-mechanical subsystems to final design level in time for the Final Design Review planned for late 2016. Eventually, Canadian industry will construct (fabricate, assemble and test) and deliver these subsystems to NRC-Herzberg for overall system integration before delivery to the TMT Observatory.

The planned out-sourced NFIRAOS subsystems, from 2014 to 2015, are:

  1. Off-Axis Paraboloids (OAP) mirrors and mounts – a total of six units are required.
  2. Beamsplitter (BS) changer with science and engineering beamsplitters, visible light BS and mounts – the science BS separates the infrared science light from the visible wavefront sensor (WFS) light and sends the science light to the client instruments. The visible light BS further separates the WFS light into laser guide star (LGS) path and visible natural WFS (VNW) path for natural guide star (NGS) wavefront sensing. The BS changer switches to the engineering BS to facilitate NFIRAOS assembly and integration.
  3. Instrument selection fold mirror (ISM), mount and rotating mechanism – the ISM reflects the infrared science light and feeds the client instruments, and the rotation mechanism directs light to the top, side and bottom instrument ports of NFIRAOS.
  4. Source simulators assembly – this contains the elements to provide artificial light sources for NGS, LGS and astrometry calibrations. The opto-mechanical components include dithering pinhole mask, deployable fold mirror for NGS sources, carriage for LGS sources, overall structural support and the associated motion control hardware.
  5. LGS path bench assembly – this contains optics, mounts and opto-mechanical mechanisms for the trombone, pickup mirrors, field stops, collimators, six optical barrels which interface with the TMT supplied detector units, overall LGS path structural support and the associated motion control hardware.
  6. VNW bench assembly – this contains optics, mounts and opto-mechanical mechanisms for the packaging fold mirrors, star selection unit, atmospheric dispersion compensator, field stop, fast steering mirrors, switchyard, and NGS optical barrel which interface with the TMT supplied detector unit, Truth wavefront sensor (TWFS) unit, overall VNW path structural support and the associated motion control hardware.
  7. High resolution wavefront sensor (HRWFS) and acquisition camera (ACQ) assembly – this contains optics, mounts and opto-mechanical mechanisms to enable high resolution wavefront sensing, low and high resolution imaging with a common detector over the full NFIRAOS field of view, and the associated motion control hardware. It also contains the overall structural support to mount the HRWFS and ACQ assembly on the side port.
  8. Turbulence generator assembly – this contains optics, mounts and opto-mechanical mechanisms to deploy the turbulence phase screen and transverse between two positions, overall structural support and the associated motion control hardware.

The opto-mechanical subsystems are illustrated in Figure 1. The total value of eight design contracts is $1.7M, ranging from $90K to $300K depending on complexity. The total value of eight construction contracts is $8.5M, ranging from $300K to $3.0M depending on complexity.

image005

NFIRAOS opto-mechanical subsystems

NFIRAOS opto-mechanical subsystems

Each contract is divided in at least in two phases, design and construction, where the latter phase will be a binding fixed-price offer for construction after successful completion of the subsystem’s final design. A public information meeting was held on Aug 28 to discuss our out-sourcing plan with potential vendors and solicit their feedback. Six companies attended the meeting.

Meerkat Reflectors

NRC Herzberg has a contract with General Dynamics Satcom (GD Satcom) to fabricate two 4 m diameter sub-reflectors and to transfer our technology to them for the fabrication of the remaining sixty two reflectors. The first two reflectors were built in Penticton and delivered before the end of our fiscal year 2013-2014. The reflectors were fabricated in a single piece from vacuum infused carbon fibre. The reflectors both had a surface RMS of 0.1 mm; easily meeting the contract specification of 0.245 mm RMS. The reflectors represent a very light (<100 kg), very simple alternative to the traditional metal multi-piece design (they come off the mold with the correct shape and require no further adjust), and the weight savings allow a further reduction in structural support weight as well as easier handling. The next phase will involve travelling to Johannesburg South Africa to train a local team to fabricate the remaining units.

Relevé spectroscopique et étude des propriétés physiques des étoiles naines blanches à moins de 40 pc du Soleil

Par/by Marie-Michèle Limoges
Thèse défendue le 18 août 2014; Thesis defended on August 18th 2014
Département de physique, université de Montréal
Directeur de thèse/thesis advisor: Pierre Bergeron (U de Montréal)
Co-directeur/co-advisor: Sébastien Lépine (Georgia State U)

Résumé (English version follows)

Les étoiles naines blanches représentent la fin de l’évolution de 97% des étoiles de notre galaxie, dont notre Soleil. L’étude des propriétés globales de ces étoiles (distribution en température, distribution de masse, fonction de luminosité, etc.) requiert l’élaboration d’ensembles statistiquement complets et bien définis. Bien que plusieurs relevés d’étoiles naines blanches existent dans la littérature, la plupart de ceux-ci souffrent de biais statistiques importants pour ce genre d’analyse. L’échantillon le plus représentatif de la population d’étoiles naines blanches demeure à ce jour celui défini dans un volume complet, restreint à l’environnement immédiat du Soleil, soit à une distance de 20 pc (∼65 années-lumière) de celui-ci. Malheureusement, comme les naines blanches sont des étoiles intrinsèquement peu lumineuses, cet échantillon ne contient que ∼ 130 objets, compromettant ainsi toute étude statistique significative. Le but de notre étude est de recenser la population d’étoiles naines blanches dans le voisinage solaire à une distance de 40 pc, soit un volume huit fois plus grand.

Nous avons ainsi entrepris de répertorier toutes les étoiles naines blanches à moins de 40 pc du Soleil à partir de SUPERBLINK, un vaste catalogue contenant le mouvement propre et les données photométriques de plus de 2 millions d’étoiles. Notre approche est basée sur la méthode des mouvements propres réduits qui permet d’isoler les étoiles naines blanches des autres populations stellaires. Les distances de toutes les candidates naines blanches sont estimées à l’aide de relations couleur-magnitude théoriques afin d’identifier les objets se situant à moins de 40 pc du Soleil, dans l’hémisphère nord. La confirmation spectroscopique du statut de naine blanche de nos ∼ 1100 candidates a ensuite requis 15 missions d’observations astronomiques sur trois grands télescopes à Kitt Peak en Arizona, ainsi qu’une soixantaine d’heures allouées sur les télescopes de 8 m des observatoires Gemini Nord et Sud. Nous avons ainsi découvert 322 nouvelles étoiles naines blanches de plusieurs types spectraux différents, dont 173 sont à moins de 40 pc, soit une augmentation de 40% du nombre de naines blanches connues à l’intérieur de ce volume. Parmi ces nouvelles naines blanches, 4 se trouvent probablement à moins de 20 pc du Soleil. De plus, nous démontrons que notre technique est très efficace pour identifier les étoiles naines blanches dans la région peuplée du plan de la Galaxie.

Nous présentons ensuite une analyse spectroscopique et photométrique détaillée de notre échantillon à l’aide de modèles d’atmosphère afin de déterminer les propriétés physiques de ces étoiles, notamment la température, la gravité de surface et la composition chimique. Notre analyse statistique de ces propriétés, basée sur un échantillon presque trois fois plus grand que celui à 20 pc, révèle que nous avons identifié avec succès les étoiles les plus massives, et donc les moins lumineuses, de cette population qui sont souvent absentes de la plupart des relevés publiés. Nous avons également identifié plusieurs naines blanches très froides, et donc potentiellement très vieilles, qui nous permettent de mieux définir le côté froid de la fonction de luminosité, et éventuellement l’âge du disque de la Galaxie. Finalement, nous avons aussi découvert plusieurs objets d’intérêt astrophysique, dont deux nouvelles étoiles naines blanches variables de type ZZ Ceti, plusieurs naines blanches magnétiques, ainsi que de nombreux systèmes binaires non résolus.

Abstract

White dwarf stars represent the endpoint of stellar evolution for 97% of stars in the Galaxy. Our own Sun, in particular, will lose its external gas layers in about 5 billion years, and end up as an Earth-sized white dwarf. The study of their global properties (temperature distribution, mass distribution, luminosity function, etc.) requires statistically complete samples, free from any selection bias, and thus the best strategy to adopt when surveying these low-luminosity objects is to restrict the search to a given volume such as the immediate vicinity of the Sun. However, the current census of white dwarfs in the solar neighborhood suffers from significant statistical biases, since the most representative sample of the local white dwarf population, i.e. the stars within a sphere with a radius of 20 pc from the Sun (∼ 65 light-years), contains only ∼ 130 objects, and is thus dominated by large uncertainties due to small-number statistics. In order to perform a statistical analysis of the local white dwarf population which is more statistically significant, we present a study aimed at obtaining a complete sample of white dwarfs in the solar neighborhood within 40 pc of the Sun, thus increasing the sampled volume by a factor of 8.

To identify every white dwarf within 40 pc of the Sun, we rely on SUPERBLINK, a large catalog containing proper motions and photometric information for over 2 million stars. Our approach is based on reduced proper motion diagrams, which are efficient at separating white dwarfs from other stellar populations. The distances for all white dwarf candidates in the northern hemisphere are determined from theoretical color-magnitude relations, in order to identify the stars that lie within 40 pc of the Sun. The spectral confirmation of the resulting ∼ 1100 candidates required 15 observing runs with 3 large telescopes at Kitt Peak, Arizona, as well as ∼ 60 hours of allocated time on the 8-m telescopes of Gemini North and South Observatories. From these spectroscopic observations, we identified 322 new white dwarf stars, among which 173 lie within 40 pc the Sun, thus increasing the current census of white dwarfs in this volume of space by 40%. Among the new white dwarf identifications, 4 could even belong to the 20 pc sample. We also show that our method is efficient at recovering white dwarfs in the densely populated area of the Galactic plane.

We then present a spectroscopic and photometric analysis of our sample with state-of-the- art model atmospheres in order to determine their physical properties, in particular the effective temperature, surface gravity, and chemical composition of each star. Our statistical analysis of these properties — based on a sample almost three times larger than the 20 pc sample—reveals that we are successfully uncovering the most massive and thus less luminous stars of this population, which are often missing in most surveys reported in the literature. We also identify a significant number of very cool and thus potentially old white dwarfs, which are useful to sample the cool end of the luminosity function used to constrain the age of the Galactic disk. Finally, we report the discovery of several objects of astrophysical interest, including two new ZZ Ceti variable stars, several magnetic white dwarfs, and a few unresolved double degenerate binaries.

e-Cassiopeia Template

fall
 

&#9808 Autumnal Equinox &#9809

Published September 23, 2014

 
 

Andromeda, as shown in an engraving from the 17th century Firmamentum Sobiescianum sive Uranographia star atlas by Johannes Hevelius. Credit: U.S. Naval Observatory and the Space Telescope Science Institute.

Andromeda, as shown in an engraving from the 17th century Firmamentum Sobiescianum sive Uranographia star atlas by Johannes Hevelius. Credit: U.S. Naval Observatory and the Space Telescope Science Institute.

In this issue:

ACURA News
An ALMA Update
NRC Herzberg News
Bulletin de CNRC Herzberg
Updates from the Canadian Gemini Office
Nouvelles de l’Office Gemini Canadien
Arctic Update
Continuing Evolution of JCMT
Mid-Term Review of LRP


Editors: Joanne Rosvick & Magdalen Normandeau
 
E-cass is CASCA’s quarterly Newsletter, published on or near the solstices and equinoxes (March 21, June 21, September 21 and December 21). To submit a contribution please email cassiopeia.editors@gmail.com. All submissions must be received at least one week in advance to be published in the next edition. We accept plain text and Word documents. Please include any images as attachments in your email, not embedded in the text.


Maunakea Spectroscopic Explorer (MSE) Project Office Now Open for Business (May 14, 2014)

The Maunakea Spectroscopic Explorer (MSE) project, formerly know as the “Next Generation CFHT”, has opened a Project Office at CFHT’s headquarters in Waimea, Hawaii, with the goal of generating a Construction Proposal over the next three years.

The Project Office is the culmination of over five years of design and feasibility studies that have demonstrated the opportunity to achieve compelling and dramatic science through upgrading CFHT into an advanced, modern and unique facility. MSE, a 10 m dedicated wide field spectroscopic telescope, will be capable of observing up to ~3200 separate objects simultaneously at spectral resolutions ranging from ~2000 – 20,000, within a ~1.5 square degrees field of view. By leveraging the exceptional image quality of the CFHT site, MSE will yield stunning new research capabilities to tackle problems ranging from dark matter, dark energy and cosmology, to galaxy evolution and structure, the archaeology of the Milky Way, stars and stellar systems, and exoplanets. Intended to support both individual programs and large scale surveys of unprecedented scale, MSE will complement the other Maunakea observatories as well as those planned for deployment worldwide and in space.

Contact Information:

  • CFHT Executive Director, Doug Simons (simons@cfht.hawaii.edu)
  • MSE Project Manager, Rick Murowinski (murowinski@mse.cfht.hawaii.edu)
  • MSE Project Scientist Alan McConnachie (mcconnachie@mse.cfht.hawaii.edu).

Additional Information: