Hello,
Ciao, Bonjour everyone. What’s up guys? Finally, I’m back with Season 2 of this
podcast. I know y’all waited for over a year for it to start airing but its
finally here. Today I will tell y’all about a mysterious object in our cosmos
which is called Himiko Cloud. Confusing right? So let me break it down in
simple terms.
Before
we understand what this Himiko cloud is, you need to know what a lyman-alpha
blob is. Because that is what this Himiko Cloud is. In astronomical terms, a
Lyman-alpha blob or LAB is a huge concentration of hydrogen gas that emits the ultraviolet
light of the Lyman-alpha emission line. They are the size of galaxies with some
of them being more than 400,000 light years across. They are one of the largest
objects in the universe. They are the early stage of the formation of galaxies.
Now you might wonder what this lyman-alpha emission line is. So let’s make it
easier to understand. Lyman-alpha is a spectral line of hydrogen spectrum which
is emitted when the electronic transition takes place from 2nd
orbital to the ground state, releasing a photon in the process which is
basically the UV light photon. I’m moving forward in this topic thinking y’all
know what this electronic transition is. You need to have this basic knowledge
in order to better understand what exactly LAB is. Also, as they are UV light
photons so how do we see them? The answer is as they are so far away, billions
of years, their light gets red-shifted to the optical part of the
electromagnetic spectrum. Moving forward, now that you know about lyman-alpha
emission line, let’s talk about our Himiko Cloud.
Himiko
Cloud was discovered back in 2009 and is indeed an object of interest for the
astronomers because it existed at a time when our universe was only 800 million
years old compared to today’s 13.1 billion years. It was found at a distance of
12.9 billion light-years and spans some 55,000 light-years. The speed of light
is finite. It means the light from this object arrived in 2009 after travelling
12.9 billion light years. So we are seeing it how it looked like as it was 12.9
billion years ago.
The
radial velocity of this object is 289575 km/s. Radial Velocity is the speed at
which an object in space is travelling away or towards the space. If the speed
is in negative then that means the object is coming towards the Sun but if the
value is positive, it means the object is going away, which is true in the case
of the Himiko Cloud. It is moving away from the Sun with the expansion of
universe.
Located
in the constellation Cetus, it was named by the scientists after one of the
mysterious 3rd century Japanese Shaman queen Himiko. Imagine how
massive this object could be? According to astronomers, it is roughly
equivalent to the mass of 40 billion Suns. This object remains a very big
mystery to the astronomers till today.
