H I region

An HI region (read H one) is a cloud in the interstellar medium composed of neutral atomic hydrogen (HI), in addition to the local abundance of helium and other elements. These regions do not emit detectable visible light (except in spectral lines from elements other than hydrogen) but are observed by the 21-cm (1,420 MHz) region spectral line. This line has a very low transition probability, so requires large amounts of hydrogen gas for it to be seen. At ionization fronts, where HI regions collide with expanding ionized gas (such as an H II region), the latter glows brighter than it otherwise would. The degree of ionization in an HI region is very small at around 10⁻⁴ (i.e. one particle in 10,000). At typical interstellar pressures in galaxies like the Milky Way, HI regions are most stable at temperatures of either below 100 K or above several thousand K; gas between these temperatures heats or cools very quickly to reach one of the stable temperature regimes. Within one of these phases, the gas is usually considered isothermal, except near an expanding H II region. Near an expanding H II region is a dense HI region, separated from the undisturbed HI region by a shock front and from the H II region by an ionization front.

Hái!

Hái! is the fourth and final album to be released by British duo The Creatures, composed of former Siouxsie and the Banshees members Siouxsie Sioux and Budgie. The album was recorded in two parts: the drums were recorded by Budgie and Kodo drummer Leonard Eto in Tokyo in August 2002 and the rest of the recording was done in Europe. During their stay in Japan, the band was inspired and "touched by the delicate snowfall imagery of Akira Kurosawa's Ikiru (1952), absorbing the vibrancy of Tokyo's Roppongi district, and spiritualised by the ancient Shinto shrines and tranquil shores of Lake Ashi."

Hái! was hailed by critics for its "Anglo-Japanese beauty".

History

In April 2002, Budgie was touring the U.S. with the Banshees, and while in Chicago, met Japanese producer Hoppy Kamiyama, known for his work with Eto. Budgie and Siouxsie had long wanted to collaborate with Eto, but had never contacted him. After an exchange of emails with Eto, The Creatures booked a studio in Tokyo and invited him to join them for a session on 19 August 2002. They approached the session in the same way as they conceived Feast: "Turn up and see what happens!". During the recording, Siouxsie took notes and stockpiled ideas for the songs. In the days that followed the session, the duo visited Roppongi district, the Shinto shrines and Lake Ashi, and shot images with a DV camera (that footage would later appear in a documentary included as a DVD in a limited edition of Hái!).

HI

HI or Hi may refer to:

The abbreviation HI or H.I. may refer to:

H&I

H&I may refer to: