From jsr at mrao.cam.ac.uk Wed Mar 3 08:55:28 2004 From: jsr at mrao.cam.ac.uk (John Richer) Date: Wed, 03 Mar 2004 13:55:28 +0000 Subject: [asac]Cambridge face-to-face Message-ID: Dear ASAC, I have put a little information together on te web to help with planning your trip to Cambridge. I've had a good response on hotel bookings, but there are still a couple of you who I have yet to hear from - if your name is not on the list on the web site and you are intending to attend, please get in touch with Kate as soon as possible. The web pages are at http://www.mrao.cam.ac.uk/~jsr/asac_may04/ I am happy to help with any further questions as they arise. All the best, John -- John Richer Astrophysics Group, Cavendish Lab, Madingley Road, Cambridge CB3 0HE http://www.mrao.cam.ac.uk/~jsr Tel: +44-1223-337246 Fax: +44-1223-354599 From soliver at nrao.edu Mon Mar 22 16:44:42 2004 From: soliver at nrao.edu (Stacy Oliver) Date: Mon, 22 Mar 2004 14:44:42 -0700 Subject: [asac][almanews] ALMA Memo 488 Released Message-ID: <005d01c41056$e2a061d0$8bdbc5ce@moonshine> ALMA Memo # 488 Wide-Field Imaging of ALMA with the Atacama Compact Array: Imaging Simulations Takahiro Tsutsumi(NAOJ), Koh-Ichiro Morita(NAOJ), Tetsuo Hasegawa(NAOJ), Jerome Pety(IRAM/Obs. de Paris) 2004-03-21 Keywords: mosaicing, wide-field imaging, simulations, ACA We examined the significance of the Atacama Compact Array (ACA) in wide-field imaging of ALMA through imaging simulations. The purpose of the simulations are to: i) demonstrate importance of ACA in wide-field imaging with ALMA and ii) identify which component of errors has more significant influence than others on quality of final images obtained with ALMA+ACA using realistic parameters as to give feedback on designing and specifications of the ACA system. We particularly focused on the following aspects: difference on the ACA configuration design and effects of pointing errors, amplitude errors, and atmospheric phase errors. The simulations indicate that how densely packed the ACA configuration is an important factor for good imaging performance. The pointing errors at submm waves seriously degrade fidelity of an image. The atmospheric phase fluctuation also plays a major role. As indicated by previous works, our study indicates that ACA can boost the quality of wide-field imaging with ALMA by a factor of two or more for many cases, while dependency on structures of model images exists. In presence of all the errors, the projected goal of the imaging fidelity of 20 or better for ALMA when ACA is included, can be achieved if the current specifications are met. View a pdf version of ALMA Memo #488. http://www.alma.nrao.edu/memos/html-memos/alma488/memo488.pdf -------------- next part -------------- An HTML attachment was scrubbed... URL: From soliver at nrao.edu Wed Mar 24 16:04:42 2004 From: soliver at nrao.edu (Stacy Oliver) Date: Wed, 24 Mar 2004 14:04:42 -0700 Subject: [asac][almanews] ALMA Memo 489 Released Message-ID: <011c01c411e3$a0cfae30$8bdbc5ce@moonshine> ALMA MEMO #489 Problems with the Homogeneous Array Simulations in ALMA Memo 488 M.A. Holdaway 2004-03-23 ALMA Memo 488 seeks to justify the building of the ACA (an array of 12 7~m antennas designed to improve the short baseline (u,v) coverage) based on its purported improvement in ALMA's imaging quality. Specifically, simulations of four different model sources are performed with the 64-element ALMA plus total power on the one hand (called ALMA+SD in Memo 488, also known as the homogeneous array), and the 64-element ALMA plus the ACA plus total power on the other hand. In several cases, adding the ACA appears to improve the image fidelity by a factor ranging from about 2 to 10 over the image quality of the 64-element ALMA without the ACA. This micro-memo points out two problems with the way these simulations were performed: first, the total power data was treated differently for the ALMA+SD and the ACA cases, with insufficient total power data being added to the ALMA+SD case; second, the observations are for a source right at the zenith, which will be the absolute worst case for homogeneous array mosaicing. We stress that homogeneous array mosaicing will often offer some advantages over mosaicing with ALMA supplemented by ACA data, and homogeneous array mosaicing will be a useful observing mode for ALMA. Adding well-calibrated ACA data will never hurt ALMA imaging, but the quoted improvement is overstated, and in many cases, thermal noise and other errors will result in essentially no improvement from the ACA data. View a pdf version of ALMA Memo #489. http://www.alma.nrao.edu/memos/html-memos/alma489/memo489.pdf -------------- next part -------------- An HTML attachment was scrubbed... URL: From awootten at nrao.edu Fri Mar 19 10:52:45 2004 From: awootten at nrao.edu (Al Wootten) Date: Fri, 19 Mar 2004 10:52:45 -0500 Subject: [asac][almanews]SECOND ANNOUNCEMENT ALMA Science Workshop May 14 - 15, 2004 U. Md. Message-ID: <16475.5965.175063.464432@polaris.cv.nrao.edu> ALMA Science Workshop May 14 - 15, 2004 College Park, Maryland WWW Site http://www.nrao.edu/almaworkshop ---------------------------------------------------------------------- SECOND ANNOUNCEMENT ---------------------------------------------------------------------- DEADLINE DATES to REMEMBER 15 April Deadline for $150 pre-registration 15 April Deadline for submission of abstracts. 14 May Meeting begins (8 am). Meeting Banquet and Cash Bar Discussion. 15 May Meeting ends, lunch begins (12:30 pm) The 'ALMA Science Workshop' meeting will take place on 14-15 May 2004 at the University of Maryland Inn and Conference Center under sponsorship of Associated Universities, Inc. (AUI), the National Radio Astronomy Observatory (NRAO) and the University of Maryland Department of Astronomy. Material on the ALMA Project may be found on the web at URL http://www.alma.nrao.edu/ If you have not yet registered, please do so, as fees will increase after 15 April, 2004. You may do this over the Web at the site whose URL is given above. In this announcement we include information on registration, the format of the meeting, information on abstracts and the Proceedings, the hotel and banquet arrangements, some travel information, and a summary of important deadlines. This announcement will be available at the WWW site, with updated information as available. http://www.nrao.edu/almaworkshop/ This email is addressed to all of those who have registered, who are on one of the organizing committees, who have been invited to present a paper at the conference, or who have previously expressed interest in the ALMA project. ---------------------------------------------------------------------- REGISTRATION The registration fee is $150 before 15 April, rising to $180 after that date. You may register at the URL http://www.astro.umd.edu/alma/registration.html Please do so if you have not already. On Friday evening, 14 May, there will be a banquet at the Inn and Conference Center. All meals, including this one, are included in the conference registration fee. You may pay by check made payable to: University of Maryland If you plan to attend the Conference, please send a printout of the registration form, with payment, to: ALMA Science Workshop Astronomy Department University of Maryland College Park, MD 20742 ---------------------------------------------------------------------- MEETING FORMAT In October 1999, a meeting was held in Washington, D.C. to bring together scientists working on the development of what would become ALMA to review the scientific program planned for the array and how that program interacted with the science goals of other astronomical facilities contemporaneous with it. The results of that meeting were published in Science with ALMA, ASP Conference Series Volume 235. Much of the research planned for ALMA at that meeting, augmented by material in the ESO Science Case for ALMA (http://www.eso.org/projects/alma/science/alma-science.pdf) has appeared in the ALMA Design Reference Science Plan (DRSP), a collection of experiments planned for the fully operational ALMA which was recently presented by the ALMA Project and which may be inspected at http://www.alma.nrao.edu/science/ The ALMA prototype antenna has made its first images; groundbreaking has occurred in Chile; NRAO's Charlottesville facilities are being revamped for ALMA support as the North American ALMA Science Center and initial ALMA Operations funding is an element of the President's budget for NRAO recently delivered to Congress. The focus of the workshop will be on ALMA and its scientist users. Astronomers are invited to discuss * ALMA's scientific goals and how best to enable them, * Science goals which might be accomplished during the ALMA Early Science Phase * The face ALMA presents to its scientists users through the North American ALMA Science Center. * Prioritization of the receiver bands for which funding will come during operations--those at 31-45 GHz, 68-90 GHz and 163-211 GHz. The conference will be organized into non-paralleled plenary sessions that are each about 2-? hours in duration beginning each day, and one paralleled workshop session on individual topics on Friday afternoon. During the Friday Plenary session there will be discussion of ALMA and the Design Reference Science Plan, followed by talks on main ALMA science themes: o Galaxies and Cosmology: A. Blain (Caltech) (40 minutes) o Star and Planet Formation: N. J. Evans (U. Texas) (40 minutes) o Stars and Their Evolution: M. Meixner (STScI) (20 minutes) o Solar Systems Near and Far: M. Gurwell (CfA) (20 minutes) During the Friday workshop sessions, there will be discussion of the science cases, including presentations on current research by those present if they wish. ALMA will begin observations as soon as enough antennas are available to make that attractive--most likely with 6 antennas by 2008. An overview of what that skeletal ALMA could be able to provide will be presented for feedback on whether that set of observing modes is optimal, or whether some effort should be expended on a somewhat different mode mix. Users will be asked for input on Early Science projects which would be interesting to them, as ALMA plans to develop an Early Science Plan to complement the DRSP (which refers only to full operation of ALMA). This will be followed by the Poster Session and Banquet, after which Paul vanden Bout will relate "The Long Random Walk to ALMA". This will be followed by a cash bar and after-dinner discussion on the topic: Building the ALMA User community: Funding, faculty, facilities On Saturday, those present will again meet in plenary session for presentation of poster summaries and reports from the working groups. This will be followed by a discussion of plans for The North American ALMA Science Center. Every poster author in each session will have the opportunity to orally present one viewgraph (in one minute) to advertise his/her poster. ---------------------------------------------------------------------- Abstracts Please provide an abstract for your poster. Please use LaTeX style forms such as are used for the Star Formation Newsletter, available at http://www.ifa.hawaii.edu/~reipurth/newsletter/macro.tex A booklet of posters will be made available at the meeting. REMINDER: Abstracts of your talks or posters are DUE NO LATER THAN: *************************************** April 15th *************************************** for publication in the booklet. The booklet which will be made available to participants at the Conference and electronically on the Web site of the Conference about one week in advance. A copy of the Conference Abstracts will be provided to the Astrophysics Data System (ADS). These will have to be prepared in LaTeX following instructions that are on the WWW. ---------------------------------------------------------------------- Accommodations The accommodations for the conference are conveniently located at the University of Maryland Inn and Conference Center. A special rate has been negotiated with the hotel. When reserving a room, please be sure to mention that you want a room within the ALMA block. The block name is "ALMA Science Meeting" and the room rate is $124.95. You may contact the hotel through Mariott reservations: Telephone: (800) 228-9290 or Facsimile: (301) 985-7445 The number of rooms at this special rate is limited in number and subject to availability. BE SURE TO RESERVE A ROOM BEFORE 15 April. Washington is very popular during April and May and rooms can be difficult to find. Details, including a map are available at the meeting WWW site: http://www.nrao.edu/almaworkshop/accomodations.shtml College Park, a suburb of Washington, D. C., is served by three major airports. Most convenient to the workshop venue is Baltimore-Washington International (BWI) Airport, which lies to the north, and has convenient rail access to the city. BWI is served by Icelandic Airways and by Southwest Airlines, along with most major airlines, and frequently boasts the most reasonably priced fares. More details may be found on the website at: http://www.nrao.edu/almaworkshop/transportation.shtml _______________________________________________ Almanews mailing list Almanews at listmgr.cv.nrao.edu http://listmgr.cv.nrao.edu/mailman/listinfo/almanews