了解宇宙是如何运行的（2010）

How the Universe Works S09E01

Part 6 March 16, 2022, 8:54 a.m.

we pass the remnants
那些被吞噬的小星系的
of smaller galaxies
eaten over the last
残留物
10 billion years.
它们揭示了M87星系是如何变得如此巨大的
They reveal how the M87
galaxy got so vast.
大多数被吞噬的星系
Most of these consumed
galaxies probably had
可能都有自己的超大质量黑洞
a supermassive black hole
of their own.
如果M87通过吞噬星系而变得如此巨大
If M87 got so large
by eating galaxies,
那么M87星是否通过
did M87 star get supermassive
吞噬其他超大质量黑洞而变得超大质量呢？
by consuming other
supermassive black holes?
所以当星系合并时，它们所有的恒星和星云
So when galaxies merge,
all their stars and nebulae
混合在一起，然后超大质量的黑洞
mix together, and then also
there supermassive black holes
最终会找到彼此并找到
eventually find each other
and find their way down to
新合并星系的中心
the center of the newly
merged galaxy.
就像把两块石头扔进池塘一样
Just like dropping
two stones into a pond,
它们都会沉到底
they'll both reach the bottom.
它们都会向中心移♥动♥
They'll both move toward
the center,
它们会越来越接近彼此
and they will start to move
ever closer together.
但是超大质量黑洞真的
But do
the supermassive black holes
会发生碰撞吗？
actually collide?
我们见证了更小的恒星质量黑洞的合并
We've witnessed
the merging of smaller,
我们也见证了
stellar mass black holes,
超大质量黑洞的靠近
and we've seen supermassive
black holes get close together,
但我们从未观察到它们的合并
but we've never observed
them merge.
当星系合并时
When galaxies merge,
their central,
它们中心的超大质量黑洞也会合并
supermassive black holes
should merge.
合并过程的第一步
The first step
in the merger process,
它们向新形成星系的中心
they're sinking toward
the center of
往下沉
this newly formed galaxy.
当超大质量的黑洞
As they plunge towards
the galactic center,
向星系中心俯冲时它们穿过了
the supermassive black holes
plow through fields
恒星区和气体云
of stars and clouds of gas.
它们不只是相互碰撞
They don't just run into
each other,
它们会相互向对方挺进
they inspiral toward each
other, so they're gonna
所以它们会将恒星分散到各处，它们越靠近彼此
scatter stars everywhere,
and the closer they get
它们围绕彼此运行的速度就越快
the more rapidly
they will orbit each other.
所以事情变得越来越混乱和疯狂
So things get even more
and more chaotic and crazy.
在所有的混乱中，奇怪的事情发生了
In all the chaos,
something strange happens.
超大质量黑洞不再
The supermassive black holes
stop moving
彼此靠近
closer to each other.
这是一个问题，我们称之为最后的秒差距问题
This is a problem, and we call
this the final parsec problem.
那么到底发生了什么？
So what's going on?
为什么会“抛锚”？
Why do they stall?
明加雷利:最后一个秒差距问题
MINGARELLI:
The final parsec problem
发生在两个超大质量黑洞耗尽
happens when two supermassive
black holes run out
帮助它们合并的材料时
of material to help them
to merge.
如果没有足够多的恒星或气体
If there's not
enough stars or gas
可以与黑洞相互作用
that the black holes can
interact with,
它们需要比宇宙年龄更长的时间
it takes longer than the age of
来失去足够的能量来合并
the universe for them to lose
enough energy to merge.
所以黑洞在这最后一秒差距的
And so the black holes
effectively stall
距离中实际上停止了
at this final parsec
of separation.
两个超大质量的黑洞
The two supermassive
black holes lock
在永恒的宇宙舞蹈中锁在一起
together in an eternal
cosmic dance,
距离很近但永远相隔
close but forever apart.
但一些超大质量黑洞一定是合并了
But some supermassive
black holes must have merged.
很有可能M87吞噬的许多星系
It's highly likely that many of
都有超大质量的黑洞
the galaxies M87 swallowed
had supermassive black holes.
然而，在我们的旅行中
And yet, on our trip,
我们并没有看到很多超大质量黑洞
we haven't seen lots of
supermassive black holes,
除了这一个……M87星
just one... M87 star.
所以合并确实发生了，但怎么发生呢？
So mergers take place, but how?
2019年，我们从一个
In 2019, we got a clue
名为 NGC 6240 的星系获得了一条线索
from a galaxy called NGC 6240.
这个特殊的星系看起来
This particular galaxy
looks like
像是一次巨大的星系碰撞后的产物
the aftermath of a massive
galactic collision.
那里有星团
There are lumps
and clumps of stars,
有任意方向和速度的
random groups
at random directions
任意星团
and random velocities.
它们都混在一起了，这就是我们认为的
It's all mixed up,
which is what we think
星系在大规模合并后的样子
galaxies look like after
a massive merger.
合并的后果揭示了
The merger aftermath
reveals a more
比两个星系碰撞更复杂的一系列事件
complex series of events
than a two-galaxy collision.
我们在这个星系的中心发现的不是两个
What we find in the center of
this galaxy isn't two,
而是三个巨大的黑洞
but three giant black holes,
这表明在最近的历史中
which suggests that there have
been three galaxies
有三个星系发生过碰撞
colliding in recent history.
明加雷利:所以，当这个新的星系
MINGARELLI: So when
this new galaxy starts to merge
开始存在这对停滞的黑洞时
with the galaxy that hosts
the stalled pair,
它会带来了它们的第三个超大质量黑洞
it brings in its own third
supermassive black hole.
现在这另一个超大质量的黑洞扰乱了这个系统
Now this supermassive black
hole perturbs the system,
使得星系中心的东西变得非常不稳定
and it makes what's at
the center highly unstable.
第三个超大质量黑洞的引力
The gravity of this third
supermassive black hole steals
从失速的黑洞中窃取轨道能量
orbital energy from
the stalled pair,
从而将它们推得更近
pushing them closer together.
它就像一个小偷，从这个
It's almost a thief
that comes in and takes away
双黑洞系统中拿走了一些
some of that rotational energy
from this binary
转动能量
black hole system.
当两个超大质量黑洞
As the two
supermassive black holes
失去轨道能量时，它们终于走到了一起
lose orbital energy,
they finally come together.
最有可能发生的事情是，最小质量的
The likeliest thing to happen
is that the least massive
超大质量黑洞被喷射出去
supermassive black hole
is ejected.
剩下的两个很快就合并了
And the remaining
two merge very quickly.
高速合并只会持续几毫秒
The high-speed merger will
last just milliseconds,
但它会引发
but it will trigger
[爆♥炸♥]
[explosion blasts]
巨大的爆♥炸♥
A gigantic explosion.