Astronomy C

[EKT26]

I guess I'll take it...?

The attached image will be needed to answer the following questions.

1. What DSO is depicted in this image?
2. When this cluster was first discovered, astronomers were unsure if it was a true galaxy cluster, or one just forming. Observations in what wavelength proved this to be a true galaxy cluster?
3. About how far away is this galaxy cluster (billion light-years)?
4. At least 19 galaxies have been confirmed to be in this cluster. What measurement can we make to determine if a galaxy is in the same cluster as galaxies that appear in the same field?

Click to Show Answer

a. JKCS 041
b. X-ray
c. 9.9 bly
d. redshift?

[RiverWalker88]

I guess I'll take it...?

The attached image will be needed to answer the following questions.

1. What DSO is depicted in this image?
2. When this cluster was first discovered, astronomers were unsure if it was a true galaxy cluster, or one just forming. Observations in what wavelength proved this to be a true galaxy cluster?
3. About how far away is this galaxy cluster (billion light-years)?
4. At least 19 galaxies have been confirmed to be in this cluster. What measurement can we make to determine if a galaxy is in the same cluster as galaxies that appear in the same field?

Click to Show Answer

a. JKCS 041
b. X-ray
c. 9.9 bly
d. redshift?

Click to Show Answer

a. Yep
b. Yep
c. Yep (although the Chandra site says 10.2 bly, as well)
d. Yep. You would need to measure distance (or redshift would work too), and galaxies that are clustered would have the same distance/redshift.

Edit: Added note on c.

[EKT26]

Guess it's my turn to give a question

There's a link to an image of a galaxy spectra with the x axis in angstroms:

What type of galaxy is it (spiral, irr, elliptical, etc.)?
What is a general trend of the spectra that can be used to identify it?
What are 3 or more specific lines that can be used to identify it?
Bonus: Give the redshift

https://drive.google.com/file/d/1NntOlL ... sp=sharing

edit: image broke pls help

[RiverWalker88]

If something here breaks, it's probably because this was a saved draft message and IDK what I'm doing when it comes to drafts.

Guess it's my turn to give a question

There's a link to an image of a galaxy spectra with the x axis in angstroms:

What type of galaxy is it (spiral, irr, elliptical, etc.)?
What is a general trend of the spectra that can be used to identify it?
What are 3 or more specific lines that can be used to identify it?
Bonus: Give the redshift

https://drive.google.com/file/d/1NntOlL ... sp=sharing

edit: image broke pls help

Click to Show Answer

a. Given the numerous absorption lines in the spectrum, I am lead to believe that star-formation is not presently occurring, so this is elliptical.
b. The numerous absorption lines. This indicates that star formation is not present.
c. Calcium Lines (around 3900 Å), Magnesium (5175 Å), Sodium (5900 Å)

Bonus: The magnesium line appears around 5200 Å, so using , I get 0.00483. This appears to be a relatively close elliptical .

Also, for images, I normally either use a discord link (they don't tend to expire), or I just attach the image (the "Attachments" tab in the box under the response box) to dodge all school-blocking (assuming scioly.org isn't blocked).

[EKT26]

If something here breaks, it's probably because this was a saved draft message and IDK what I'm doing when it comes to drafts.

Guess it's my turn to give a question

There's a link to an image of a galaxy spectra with the x axis in angstroms:

What type of galaxy is it (spiral, irr, elliptical, etc.)?
What is a general trend of the spectra that can be used to identify it?
What are 3 or more specific lines that can be used to identify it?
Bonus: Give the redshift

https://drive.google.com/file/d/1NntOlL ... sp=sharing

edit: image broke pls help

Click to Show Answer

a. Given the numerous absorption lines in the spectrum, I am lead to believe that star-formation is not presently occurring, so this is elliptical.
b. The numerous absorption lines. This indicates that star formation is not present.
c. Calcium Lines (around 3900 Å), Magnesium (5175 Å), Sodium (5900 Å)

Bonus: The magnesium line appears around 5200 Å, so using , I get 0.00483. This appears to be a relatively close elliptical .

Also, for images, I normally either use a discord link (they don't tend to expire), or I just attach the image (the "Attachments" tab in the box under the response box) to dodge all school-blocking (assuming scioly.org isn't blocked).

All of those are correct.
It’s you’re turn!

[RiverWalker88]

Galactic Jets in Radio Galaxies

1. Radio galaxies always have a set of powerful jets leading from the black hole. Because of these jets, what can we infer about the spin rate of the black hole?
2. What major feature of radio galaxies is caused by these jets?
3. Most radio galaxies are elliptical. What property of elliptical galaxies make us believe that the matter that feeds the AGN is from external origin (i.e. not directly from the host galaxy)?
4. What might this matter of external origin come from?

[Name]

Galactic Jets in Radio Galaxies

1. Radio galaxies always have a set of powerful jets leading from the black hole. Because of these jets, what can we infer about the spin rate of the black hole?
2. What major feature of radio galaxies is caused by these jets?
3. Most radio galaxies are elliptical. What property of elliptical galaxies make us believe that the matter that feeds the AGN is from external origin (i.e. not directly from the host galaxy)?
4. What might this matter of external origin come from?

attempt (Click to Show Hidden Text)

1. uh the jets are due to synchrotron radiation, which implies a high spin rate of the black hole?
2. active galactic nuclei, or more specifically a quasar
3. The mass of the galaxy closely correlates to the mass of the black hole. this would not be the case if the AGN feeds only from the host galaxy as the ratio of black hole mass to galaxy mass would increase over time, leading to differently aged elliptical galaxies having different ratios of black hole mass to galaxy mass. As both are correlated, there must be mass of outside origin feeding into both the galaxy and the black hole.
4. galaxy collisions and cannibalism 

[RiverWalker88]

Galactic Jets in Radio Galaxies

1. Radio galaxies always have a set of powerful jets leading from the black hole. Because of these jets, what can we infer about the spin rate of the black hole?
2. What major feature of radio galaxies is caused by these jets?
3. Most radio galaxies are elliptical. What property of elliptical galaxies make us believe that the matter that feeds the AGN is from external origin (i.e. not directly from the host galaxy)?
4. What might this matter of external origin come from?

attempt (Click to Show Hidden Text)

1. uh the jets are due to synchrotron radiation, which implies a high spin rate of the black hole?
2. active galactic nuclei, or more specifically a quasar
3. The mass of the galaxy closely correlates to the mass of the black hole. this would not be the case if the AGN feeds only from the host galaxy as the ratio of black hole mass to galaxy mass would increase over time, leading to differently aged elliptical galaxies having different ratios of black hole mass to galaxy mass. As both are correlated, there must be mass of outside origin feeding into both the galaxy and the black hole.
4. galaxy collisions and cannibalism 

Click to Show Answer

a. Yep
b. I was looking more for radio lobes here, an AGN isn't necessarily caused by the jets...
c. Uhhh... I can't verify if this is right or wrong. I was mainly considering that elliptical galaxies having low amounts of the cool gas that feeds an AGN. Your answer seems pretty reasonable too, though...
d. Yep

[Name]

Let's look at 3C273 and AGNs
1. What type of quasar is 3C273 (radio-loud or quiet)? What does being a radio-loud quasar mean? Which type of quasar is more common?
2. Some quasars create the illusion of multiple quasars in close proximity, yet is only one quasar. What causes this illusion?
3. Classify the following AGNs on the type of galaxy they are most likely to appear in- Seyfert 1, Seyfert 2, Quasars, Radio galaxies (Ex. Spiral Galaxy)
4. Seyfert 1 and Quasar AGNs are observed to have broad emission lines. What causes these emission lines?

[AstroClarinet]

Let's look at 3C273 and AGNs
1. What type of quasar is 3C273 (radio-loud or quiet)? What does being a radio-loud quasar mean? Which type of quasar is more common?
2. Some quasars create the illusion of multiple quasars in close proximity, yet is only one quasar. What causes this illusion?
3. Classify the following AGNs on the type of galaxy they are most likely to appear in- Seyfert 1, Seyfert 2, Quasars, Radio galaxies (Ex. Spiral Galaxy)
4. Seyfert 1 and Quasar AGNs are observed to have broad emission lines. What causes these emission lines?

Click to Show Answer

1. 3C 273 is radio-loud. Radio-loud quasars have high amounts of radio emission, but radio-quiet quasars are more common.
2. Gravitational lensing 
3. Seyfert 1 & 2 - spiral, Radio galaxies - elliptical, Quasars - elliptical?
4. The broad line region - fast-moving gas clouds which absorb & re-emit light from the accretion disk as broad emission lines because of Doppler broadening (due to their high speeds).