Meddelelse
ALMA bliver endnu bedre til at observere i endnu kortere bølgelængder
10. september 2014
ALMA (The Atacama Large Millimeter/submillimeter Array) har nået endnu en milepæl i sin planlagte udvikling. Nu kan anlægget observere helt ude i submillimeterområdet. Der finder man stråling, som fortæller om det kolde, mørke og meget fjerne Univers.
Det nye udstyr åbner et helt nyt vindue til Universet for ALMA. Nu kan der også observeres i "bånd )". Det betyder samtidig at ALMA nu er fuldt udbygget, så astronomer over hele verden fuldt ud kan få glæde af anlægget.
De nye muligheder demonstreres ved et nyt billede af planeten Uranus, som den ser ud i lys i submillimeterområdet. Billedet er netop blevet offentliggjort af det hold, som overvåger, at ALMA lever op til specifikationerne. Uranusbilledet - som er optaget i det mest kortbølgede område, som er muligt - viser det kolde lys fra planetens atmosfære. Her hersker der temperaturer helt ned til -224°C, og det er den koldeste atmosfære i Solsystemet. Med det nye udstyr kan astronomer og planetforskere studere temperaturforandringer i forskellige højder over Uranus' skydække, og det samme kan gøres ved de andre kæmpeplaneter i Solsystemet.
Lederen af ibrugtagelsen af teleskopet er Satoko Takahashi fra National Astronomical Observatory of Japan. Han siger: "Inden vi kunne begynde at bruge anlægget ved disse korte bølgelængder, var det nødvendigt at gennemteste alt, og at finde frem til de observationsprocedurer, som giver de mest nøjagtige resultater. Det er det, der gør, at ibrugtagningsarbejdet er så vigtigt".
ALMA observerer ud i verdensrummet ved hjælp af en serie meget fint justerede modtagere, som er installeret i hver af anlæggets 66 antenner. Hver type modtager er følsom i et specielt "bånd", eller interval af bølgelængder i det elektromagnetiske spektrum. Bånd 10 modtagerne er installerede og afprøvede i de fleste af antennerne, og resten følger i løbet af de næste måneder.
Afprøvningsholdet er i gang med at forfine to nye observationsteknikker, som kan forøge den tid, hvori ALMA kan studere Universet i de kortere bølgelængder.
Den første metode kaldes "bånd til bånd overførsel". I dårlige vejrforhold er det muligt først at observere et objekt på himlen i en længere bølgelængde, og dernæst bruge disse data til at finjustere teleskopet til observationer i kortere bølgelængder.
En anden teknik består i først at observere i et meget bredt bølgelængdeområde, hvorefter man indsnævrer intervallet til et snævert kortbølget område. Denne metoder bliver snart rutine, selvom ALMA er det eneste anlæg, hvor den kan anvendes. De to metoder tilsammen gør det muligt at få mange flere timer med gode observationer, end det ellers var muligt. Nye hold astronomer er nu på vej til ALMA for at arbejde videre med de nye teknikker.
Flere oplysninger
ALMA, Atacama Large Millimeter/submillimeter Array, er et internationalt astronomisk observatorium, hvor Europa, Nordamerika og Østasien samarbejder med Chile. ALMAs europæiske del finansieres af ESO (Det europæiske sydobservatorium), I Nordamerika er det USAs National Science Foundation i samarbejde med Canadas National Research Council og National Science Council i Taiwan, og i Østasien er det National Institutes of Natural Sciences, Japan og Academia Sinica, Taiwan, som betaler. Opbygningen og driften af ALMA varetages i Europa af ESO, i USA af National Radio Astronomy Observatory og i Østasien af National Astronomical Observatory of Japan. Organisationen Joint ALMA Observatory, JAO står for den fælles ledelse og styring af konstruktion og drift af ALMA.
Det internationale hold, som foretager afprøvningerne i High Frequency Observing Campaign ledes af Satoko Takasashi fra National Astronomical Observatory of Japan. Han er ALMAs østasiensrepræsentant. Ledelsesposten deles med Anthony Remijan fra National Radio Astronomy Observatory. Han er også ALMA Program Scientist for Extension and Optimization of Capabilities. De andre gruppemedlemmer er Catherine Vlahakis, Neil Philips, Denis Barkats, Bill Dent (JAO/ESO), Ed Fomalont, Brian Mason, Jennifer Donovan Meyer (NRAO); Violette Impellizzeri, Paulo Cortes, Christian Lopez (JAO/NRAO); Christine Wilson (NRAO/McMaster University); Seiji Kameno, Tsyuoshi Sawada (JAO/NAOJ); Tim Van Kempen, Luke Maud & Remo Tilanus (Leiden); Robert Lucas (Grenoble); Richard Hills (Cambridge); Akihiko Hirota (JAO/NAOJ) og James Chibueze (NAOJ).
Kontakter
Ole J. Knudsen
ESON-Danmark, IDA
Aarhus Universitet
tlf 8715 5419
eson-denmark@eso.org
Lars Lindberg Christensen
Head of ESO ePOD
Garching bei München, Germany
Tel: +49 89 3200 6761
Cell: +49 173 3872 621
Email: lars@eso.org
Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory
Tel: +1 434 296 0314
Cell: +1 202 236 6324
Email: cblue@nrao.edu
Masaaki Hiramatsu
National Astronomical Observatory of Japan
Japan
Tel: +81 422 34 3630
Email: hiramatsu.masaaki@nao.ac.jp
Om meddelelsen
| Id: | ann14065 |
Billeder
Our use of Cookies
We use cookies that are essential for accessing our websites and using our services. We also use cookies to analyse, measure and improve our websites’ performance, to enable content sharing via social media and to display media content hosted on third-party platforms.
ESO Cookies Policy
The European Organisation for Astronomical Research in the Southern Hemisphere (ESO) is the pre-eminent intergovernmental science and technology organisation in astronomy. It carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities for astronomy.
This Cookies Policy is intended to provide clarity by outlining the cookies used on the ESO public websites, their functions, the options you have for controlling them, and the ways you can contact us for additional details.
What are cookies?
Cookies are small pieces of data stored on your device by websites you visit. They serve various purposes, such as remembering login credentials and preferences and enhance your browsing experience.
Categories of cookies we use
Essential cookies (always active): These cookies are strictly necessary for the proper functioning of our website. Without these cookies, the website cannot operate correctly, and certain services, such as logging in or accessing secure areas, may not be available; because they are essential for the website’s operation, they cannot be disabled.
Functional Cookies: These cookies enhance your browsing experience by enabling additional features and personalization, such as remembering your preferences and settings. While not strictly necessary for the website to function, they improve usability and convenience; these cookies are only placed if you provide your consent.
Analytics cookies: These cookies collect information about how visitors interact with our website, such as which pages are visited most often and how users navigate the site. This data helps us improve website performance, optimize content, and enhance the user experience; these cookies are only placed if you provide your consent. We use the following analytics cookies.
Matomo Cookies:
This website uses Matomo (formerly Piwik), an open source software which enables the statistical analysis of website visits. Matomo uses cookies (text files) which are saved on your computer and which allow us to analyze how you use our website. The website user information generated by the cookies will only be saved on the servers of our IT Department. We use this information to analyze www.eso.org visits and to prepare reports on website activities. These data will not be disclosed to third parties.
On behalf of ESO, Matomo will use this information for the purpose of evaluating your use of the website, compiling reports on website activity and providing other services relating to website activity and internet usage.
Matomo cookies settings:
Additional Third-party cookies on ESO websites: some of our pages display content from external providers, e.g. YouTube.
Such third-party services are outside of ESO control and may, at any time, change their terms of service, use of cookies, etc.
YouTube: Some videos on the ESO website are embedded from ESO’s official YouTube channel. We have enabled YouTube’s privacy-enhanced mode, meaning that no cookies are set unless the user actively clicks on the video to play it. Additionally, in this mode, YouTube does not store any personally identifiable cookie data for embedded video playbacks. For more details, please refer to YouTube’s embedding videos information page.
Cookies can also be classified based on the following elements.
Regarding the domain, there are:
- First-party cookies, set by the website you are currently visiting. They are stored by the same domain that you are browsing and are used to enhance your experience on that site;
- Third-party cookies, set by a domain other than the one you are currently visiting.
As for their duration, cookies can be:
- Browser-session cookies, which are deleted when the user closes the browser;
- Stored cookies, which stay on the user's device for a predetermined period of time.
How to manage cookies
Cookie settings: You can modify your cookie choices for the ESO webpages at any time by clicking on the link Cookie settings at the bottom of any page.
In your browser: If you wish to delete cookies or instruct your browser to delete or block cookies by default, please visit the help pages of your browser:
Please be aware that if you delete or decline cookies, certain functionalities of our website may be not be available and your browsing experience may be affected.
You can set most browsers to prevent any cookies being placed on your device, but you may then have to manually adjust some preferences every time you visit a site/page. And some services and functionalities may not work properly at all (e.g. profile logging-in, shop check out).
Updates to the ESO Cookies Policy
The ESO Cookies Policy may be subject to future updates, which will be made available on this page.
Additional information
For any queries related to cookies, please contact: pdprATesoDOTorg.
As ESO public webpages are managed by our Department of Communication, your questions will be dealt with the support of the said Department.