An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

<< < act Sun > >>

Number of Results: 23 Search : sun
Sunyaev-Zel'dovich effect
  اُسکر ِ سونیایف-زلدوویچ   
oskar-e Sunyaev-Zeldovich

Fr.: effet Sunyaev-Zel'dovich   

The loss of energy by high-energy electrons in a → galaxy cluster, which distorts the → cosmic microwave background (CMB) radiation through → inverse Compton effect. When photons from the CMB radiation travel through a hot plasma (with a temperature of around 108 K), in which bathe a galaxy cluster, they collide with energetic electrons and some of the energy of the electrons is transferred to the low energy CMB photons. If we look at the CMB radiation through such a plasma cloud, we therefore see fewer microwave photons than we would if the cloud were not there.

Named after Rashid Sunyaev (1943-) and Yakov Borisovich Zel'dovich (1914-1987), Russian astrophysicists; → effect.

true Sun
  خورشید ِ راستین   
xoršid-e râstin

Fr.: Soleil vrai   

The Sun as seen in the sky, also referred to as the → apparent Sun; in opposition to → mean Sun.

true; → Sun.

tsunami
  تسونامی   
tsunami (#)

Fr.: tsunami   

A huge wave, caused by undersea earthquakes, volcanic eruptions, or, more rarely, by asteroid or meteoroid impact (as in the case of the K-T extinction).

From Japanese tsunami, from tsu "harbor" + nami "waves."

<< < act Sun > >>