BLOB$500963$ - tradução para holandês
![Aquarius]]. Credit [[ESO]]/M. Hayes.](https://commons.wikimedia.org/wiki/Special:FilePath/Lyman-alpha blob LAB-1.jpg?width=200 "Aquarius]]. Credit [[ESO]]/M. Hayes.")
![Algorithm]] of the management of a pregnancy of unknown location, that is, a positive pregnancy test but no pregnancy is found on [[transvaginal ultrasonography]].<ref name=kirk2013/> If serum hCG at 0 hours is more than 1000 IU/L and there is no history suggestive of complete miscarriage, the ultrasonography should be repeated as soon as possible.<ref name=kirk2013/>](https://commons.wikimedia.org/wiki/Special:FilePath/Algorithm in pregnancy of unknown location.svg?width=200 "Algorithm]] of the management of a pregnancy of unknown location, that is, a positive pregnancy test but no pregnancy is found on [[transvaginal ultrasonography]].<ref name=kirk2013/> If serum hCG at 0 hours is more than 1000 IU/L and there is no history suggestive of complete miscarriage, the ultrasonography should be repeated as soon as possible.<ref name=kirk2013/>")
![Left fallopian tube with an ectopic pregnancy in a 25-year-old woman after a [[salpingectomy]]](https://commons.wikimedia.org/wiki/Special:FilePath/EUG 2.png?width=200 "Left fallopian tube with an ectopic pregnancy in a 25-year-old woman after a [[salpingectomy]]")
![Blood in [[Morrison's pouch]] between the liver and kidney due to a ruptured ectopic pregnancy](https://commons.wikimedia.org/wiki/Special:FilePath/FluidMorisonsPouchEctop.PNG?width=200 "Blood in [[Morrison's pouch]] between the liver and kidney due to a ruptured ectopic pregnancy")
![[[Chorionic villus]] on [[histopathological examination]] of a tubal pregnancy](https://commons.wikimedia.org/wiki/Special:FilePath/Histopathology of tubal pregnancy.jpg?width=200 "[[Chorionic villus]] on [[histopathological examination]] of a tubal pregnancy")
![[[Transvaginal ultrasonography]] of an ectopic pregnancy, showing the field of view in the following image](https://commons.wikimedia.org/wiki/Special:FilePath/Schematic figure of vaginal ultrasonography in ectopic pregnancy.svg?width=200 "[[Transvaginal ultrasonography]] of an ectopic pregnancy, showing the field of view in the following image")
![intrauterine device (IUD) with progestogen]], whose cross-section is visible in the field, leaving an ultrasound shadow distally to it.](https://commons.wikimedia.org/wiki/Special:FilePath/Blob sign of ectopic pregnancy.png?width=200 "intrauterine device (IUD) with progestogen]], whose cross-section is visible in the field, leaving an ultrasound shadow distally to it.")
![Ultrasound image showing an ectopic pregnancy where a [[gestational sac]] and fetus has been formed](https://commons.wikimedia.org/wiki/Special:FilePath/Ectopicleftmass.PNG?width=200 "Ultrasound image showing an ectopic pregnancy where a [[gestational sac]] and fetus has been formed")
Wikipédia
In astronomy, a Lyman-alpha blob (LAB) is a huge concentration of a gas emitting the Lyman-alpha emission line. LABs are some of the largest known individual objects in the Universe. Some of these gaseous structures are more than 400,000 light years across. So far they have only been found in the high-redshift universe because of the ultraviolet nature of the Lyman-alpha emission line. Since Earth's atmosphere is very effective at filtering out UV photons, the Lyman-alpha photons must be redshifted in order to be transmitted through the atmosphere.
The most famous Lyman-alpha blobs were discovered in 2000 by Steidel et al. Matsuda et al., using the Subaru Telescope of the National Astronomical Observatory of Japan extended the search for LABs and found over 30 new LABs in the original field of Steidel et al., although they were all smaller than the originals. These LABs form a structure which is more than 200 million light-years in extent. It is currently unknown whether LABs trace overdensities of galaxies in the high-redshift universe (as high redshift radio galaxies—which also have extended Lyman-alpha halos—do, for example), nor which mechanism produces the Lyman-alpha emission line, or how the LABs are connected to the surrounding galaxies. Lyman-alpha blobs may hold valuable clues to determine how galaxies are formed.
The most massive Lyman-alpha blobs have been discovered by Tristan Friedrich et al. (2021), Steidel et al. (2000), Francis et al. (2001), Matsuda et al. (2004), Dey et al. (2005), Nilsson et al. (2006), and Smith & Jarvis et al. (2007).
