跳至內容

File:Quasars Acting as Gravitational Lenses.jpg

頁面內容不支援其他語言。
這個檔案來自維基共享資源
維基百科,自由的百科全書

原始檔案 (1,061 × 532 像素,檔案大小:262 KB,MIME 類型:image/jpeg


摘要

描述
English: Astronomers using the NASA/ESA Hubble Space Telescope have made images of several galaxies containing quasars, which act as gravitational lenses to amplify and distort images of the galaxies aligned behind them.

Quasars are among the brightest objects in the Universe, far outshining the total output of their host galaxies. They are powered by supermassive black holes, which pull in surrounding material that then heats up as it falls towards the black hole. The path that the light from even more distant galaxies takes on its journey towards us is bent by the enormous masses at the centre of these galaxies. Gravitational lensing is a subtle effect which requires extremely high resolution observations, something for which Hubble is extremely well suited.

To find these rare cases of galaxy–quasar combinations acting as lenses, a team of astronomers led by Frederic Courbin at the Ecole Polytechnique Federale de Lausanne (EPFL, Switzerland) selected 23 000 quasar spectra in the Sloan Digital Sky Survey (SDSS). They looked for the spectral imprint of galaxies at much greater distances that happened to align with foreground galaxies. Once candidates were identified, Hubble’s sharp vision was used to look for the characteristic gravitational arcs and rings that would be produced by gravitational lensing.

In Hubble’s images, the quasars are the bright spots visible at the centre of the galaxies, while the lensed images of distant galaxies are visible as fainter arc-shaped forms that surround them. From left to right, the galaxies are: SDSS J0919+2720, with two bluish lensed images clearly visible above and below the galaxy’s centre; SDSS J1005+4016, with one yellowish arc visible to the right of the galaxy’s centre; and SDSS J0827+5224, with two lensed images very faintly visible, one above and to the right, and one below and to the left of the galaxy’s centre.

Quasar host galaxies are hard or sometimes even impossible to see because the central quasar far outshines the galaxy. Therefore, it is difficult to estimate the mass of a host galaxy based on the collective brightness of its stars. However, gravitational lensing candidates are invaluable for estimating the mass of a quasar’s host galaxy because the amount of distortion in the lens can be used to estimate a galaxy’s mass.
日期
來源 http://www.spacetelescope.org/images/potw1212a/
作者 NASA, ESA/Hubble and F. Courbin (Ecole Polytechnique Federale de Lausanne, Switzerland)

授權條款

w:zh:共享創意
姓名標示
此檔案採用創用CC 姓名標示 3.0 未在地化版本授權條款。
您可以自由:
  • 分享 – 複製、發佈和傳播本作品
  • 重新修改 – 創作演繹作品
惟需遵照下列條件:
  • 姓名標示 – 您必須指名出正確的製作者,和提供授權條款的連結,以及表示是否有對內容上做出變更。您可以用任何合理的方式來行動,但不得以任何方式表明授權條款是對您許可或是由您所使用。

說明

添加單行說明來描述出檔案所代表的內容

在此檔案描寫的項目

描繪內容

著作權狀態 繁體中文 (已轉換拼寫)

有著作權 繁體中文 (已轉換拼寫)

共享創意署名3.0未本地化 Chinese (Hong Kong) (已轉換拼寫)

多媒體型式 繁體中文 (已轉換拼寫)

image/jpeg

檔案歷史

點選日期/時間以檢視該時間的檔案版本。

日期/時間縮⁠圖尺寸用戶備⁠註
目前2019年10月26日 (六) 15:07於 2019年10月26日 (六) 15:07 版本的縮圖1,061 × 532(262 KB)BevinKaconactual size from source
2012年3月19日 (一) 11:52於 2012年3月19日 (一) 11:52 版本的縮圖1,280 × 642(185 KB)Jmencisom

下列頁面有用到此檔案:

全域檔案使用狀況

以下其他 wiki 使用了這個檔案:

詮釋資料