What Would The Milky Way Look Like If You Could See All Of Its Light?
“When you look at the Milky Way in visible light, you might see billions of stars, but you miss so much more. The human eye is only sensitive to a tiny fraction of the entire electromagnetic (light) spectrum. Each wavelength range showcases a novel view of all that’s out there.”
If you looked out at our galaxy with your eyes and the wavelengths they’re sensitive to alone, there’s an incredible amount of information you’d miss no matter how powerful you became at gathering light or resolving individual objects. That’s because visible light only occupies a narrow range of electromagnetic wavelengths, meaning that what you can see is limited to what emits visible light (stars and some reflective clouds) and constrained by dust, which can absorb all the visible light behind it.
But there are other wavelengths than these, and they reveal a series of fascinating details. What do they all look like? Come get a fuller picture today!
The Most Important X-Ray Image Ever Taken Proved The Existence Of Dark Matter
“Yet the most important X-ray image of all time was an incredible surprise. This is the Bullet Cluster: a system of two galaxy clusters colliding at high speeds. As the gaseous matter inside collides, it slows, heats up, and lags behind, emitting X-rays. However, we can use gravitational lensing to learn where the mass is located in this system. he bending and shearing of light from background galaxies shows it’s separated from the matter’s and X-rays’ location. This separation is some of our strongest evidence for dark matter.”
There are many different lines of evidence for dark matter, but one of the biggest contentions of those who disbelieve it is that a direct empirical proof of its existence is needed. If it exists in a large, diffuse halo around every galaxy, cluster, and component of large-scale structure in the Universe, you should be able to prove it. Starting more than 10 years ago, astronomers have been able to do just that. When galaxy clusters collide, the overwhelming majority of normal matter, residing in the intracluster medium, should smash together, heat up, and emit X-rays. It does! But the biggest deal is that the gravitational mass, reconstructed through lensing, doesn’t coincide with the normal matter.
There must be some other type of matter from the normal, baryonic matter. Ergo, dark matter. Here’s (IMO) the most important X-ray story of all-time.
The Pillars Of Creation Haven’t Been Destroyed, Say New NASA Images
“Near-infrared observations can see through the dust, revealing a glittering tapestry of young, hot stars inside. But at longer wavelengths, cooler-temperature objects show up. Mid-infrared light revealed that a diffuse heat source was warming the nebula, suggesting a recent supernova. While the far-infrared showed where the gas is evaporating, we needed X-rays to know if the pillars were being destroyed.”
In a stunning new release, NASA’s Chandra X-ray observatory has put out a wide-field view of a large portion of the Eagle Nebula, including the famed Pillars of Creation. All told, some 1,700 X-ray sources were identified, perhaps 2/3rds of which are inside the nebula. There are proto-stars, young stars, and stellar corpses. But conspicuously missing from the entire field-of-view is any evidence of a supernova remnant. In 2007, infrared data from Spitzer suggested that there may have been a recent supernova, and hence the pillars may already have been destroyed. The new Chandra data weighs in on that, giving a definitive “no” for an answer.
Come see the incredible suite of images and learn about the science inside this cosmic beauty, on today’s Mostly Mute Monday!
Astrophysics Reveals The Origin Of The Human Body
“Owing to NASA’s Chandra X-ray telescope, we can observe how much of each heavy element comes from recent supernova explosions.
When it comes to the human body, the majority of what makes us up comes from supernovae, not any other source.
The biggest find? Every element required to make DNA is found in the aftermath of exploding stars.”
From hydrogen through uranium and beyond, the Universe finds a way to create more than 90 unique elements via natural processes. Dozens of those elements have been found in the human body, many of which are essential to life processes. Yet every element has its own unique cosmic origin story, from the Big Bang to small stars to supernovae to neutron star mergers and more. Using data from NASA’s Chandra X-ray telescope, we’ve measured which elements are produced in supernova explosions, and in what concentrations. Not only have we determined that the overwhelming majority of the human body’s components (73%) are produced in supernovae, but that almost all of our oxygen, by far our most abundant element, is made there. Other processes play a role, but the majority of each of us comes from an exploding, massive star.
Come find out the true, full origin of the elements that made you, a truly cosmic story!
Newest LIGO Signal Raises A Huge Question: Do Merging Black Holes Emit Light?
“The second merger held no such hints of electromagnetic signals, but that was less surprising: the black holes were of significantly lower mass, so any signal arising from them would be expected to be correspondingly lower in magnitude. But the third merger was large in mass again, more comparable to the first than the second. While Fermi has made no announcement, and Integral again reports a non-detection, there are two pieces of evidence that suggest there may have been an electromagnetic counterpart after all. The AGILE satellite from the Italian Space Agency detected a weak, short-lived event that occurred just half a second before the LIGO merger, while X-ray, radio and optical observations combined to identify a strange afterglow less than 24 hours after the merger.”
Whenever there’s a catastrophic, cataclysmic event in space, there’s almost always a tremendous release of energy that accompanies it. A supernova emits light; a neutron star merger emits gamma rays; a quasar emits radio waves; merging black holes emit gravitational waves. But if there’s any sort of matter present outside the event horizons of these black holes, they have the potential to emit electromagnetic radiation, or light signals, too. Our best models and simulations don’t predict much, but sometimes the Universe surprises us! With the third LIGO merger, there were two independent teams that claimed an electromagnetic counterpart within 24 hours of the gravitational wave signal. One was an afterglow in gamma rays and the optical, occurring about 19 hours after-the-fact, while the other was an X-ray burst occurring just half a second before the merger.
Could either of these be connected to these merging black holes? Or are we just grasping at straws here? We need more, better data to know for sure, but here’s what we’ve got so far!