APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 4840
Joined: Fri Dec 04, 2009 3:27 am

APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by APOD Robot » Sun Mar 07, 2021 5:05 am

Image Pillars of the Eagle Nebula in Infrared

Explanation: Newborn stars are forming in the Eagle Nebula. Gravitationally contracting in pillars of dense gas and dust, the intense radiation of these newly-formed bright stars is causing surrounding material to boil away. This image, taken with the Hubble Space Telescope in near infrared light, allows the viewer to see through much of the thick dust that makes the pillars opaque in visible light. The giant structures are light years in length and dubbed informally the Pillars of Creation. Associated with the open star cluster M16, the Eagle Nebula lies about 6,500 light years away. The Eagle Nebula is an easy target for small telescopes in a nebula-rich part of the sky toward the split constellation Serpens Cauda (the tail of the snake).

<< Previous APOD This Day in APOD Next APOD >>

User avatar
VictorBorun
Commander
Posts: 687
Joined: Fri Oct 16, 2020 10:25 pm

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by VictorBorun » Sun Mar 07, 2021 8:14 am

shades are quite elegant:
bluish gray of the front-lighted clouds and brown of the back-lighted clouds.

It's a cold/warm hue pair to color-code what was extracted from infrared range, isn't it?

User avatar
Ann
4725 Å
Posts: 12350
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by Ann » Sun Mar 07, 2021 9:11 am

VictorBorun wrote: Sun Mar 07, 2021 8:14 am shades are quite elegant:
bluish gray of the front-lighted clouds and brown of the back-lighted clouds.

It's a cold/warm hue pair to color-code what was extracted from infrared range, isn't it?
Not sure what the blue hues mean in this APOD. In mapped-color images, colors can be used quite haphazardly.

The important information, the way I read the image, is that the two tallest pillars have orange-glowing tops. This signifies star formation, I think.

Note, too, that the leftmost pillar has an extremely thin lower part, and the rightmost pillar basically has no "lower body" at all. By contrast, the middle pillar is relatively thick, and it is connected to a "horizontal" dust cloud in a way that makes this dust structure look like the body and the extra long neck of a horse or a donkey. It's just the head that's missing.

Or maybe the middle dust structure really looks like the living being that the nebula got its name from: The Eagle Nebula. 🦅

Ann
Color Commentator

Brad S.

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by Brad S. » Sun Mar 07, 2021 10:42 am

Hmm, the 'image' looks like the classic depiction of the Centaurus-plus-Lupus. That is, we see the traditional image of the Centaur holding up the Wolf. (For a classical image, compare to https://commons.wikimedia.org/wiki/File ... cator.jpeg .) The Centaur's horse-body stretches horizontally across the image a bit below center, with the vertical human torso (topped by a head) rising from the rightmost side of the horse-body. We see the thin legs hanging below the front and back sides of the horse-body. The arm and the spear are held out in front of the top of the torso. (Originally, the spear was identified as a mysterious 'thyrsus'.) At the end of the arm, the Centaur is holding the vertical body of the Wolf. (Originally, the animal was only identified as a 'beast'.) We see the wolf's head at the top with a pointy upturned nose, and the ear poking to the right. We see the wolf's hind leg hanging down at the bottom, and there is even the tail coming out at the right place. Everything is anatomically-correct for the classic image of the constellation figures for the Centaur plus the Wolf. It is weird that the random turbulence in these humongous gas clouds would create a well-known silhouette inside a second constellation depicting a Centaur.

Sa Ji Tario

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by Sa Ji Tario » Sun Mar 07, 2021 12:53 pm

Ann. coincided with Brad S

User avatar
orin stepanek
Plutopian
Posts: 7806
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by orin stepanek » Sun Mar 07, 2021 4:46 pm

https://apod.nasa.gov/apod/ap210307.html

Wow! I can't ever remember the pillars ever being presented like this! I like!
Orin

Smile today; tomorrow's another day!

User avatar
johnnydeep
Captain
Posts: 1592
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by johnnydeep » Sun Mar 07, 2021 5:40 pm

This is a very cool (or warm!) image. I see there's a detailed page link I still need to read all about Hubble imaging (namely, https://asd.gsfc.nasa.gov/blueshift/ind ... lse-color/), but can someone give the the executive summary of what has to change in Hubble for it to capture infra-red as opposed to visible light? Is it just swapping a different filter in place, or is there also a different sensor that is more sensitive to infrared? Obviously, the mirror itself can't change!
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."

User avatar
Chris Peterson
Abominable Snowman
Posts: 17009
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by Chris Peterson » Sun Mar 07, 2021 6:21 pm

johnnydeep wrote: Sun Mar 07, 2021 5:40 pm This is a very cool (or warm!) image. I see there's a detailed page link I still need to read all about Hubble imaging (namely, https://asd.gsfc.nasa.gov/blueshift/ind ... lse-color/), but can someone give the the executive summary of what has to change in Hubble for it to capture infra-red as opposed to visible light? Is it just swapping a different filter in place, or is there also a different sensor that is more sensitive to infrared? Obviously, the mirror itself can't change!
It is unfortunate that the filter details aren't provided. That said, "infrared" covers a very broad range. The IR that the HST can capture is pretty much the same optically as visible light. Its wavelengths are what can be detected by an ordinary silicon detector, which falls off rapidly above 1.5 micrometers. That is shorter than thermal IR. So yes... it's just a question of choosing an IR-pass filter in place of a visible light filter. The camera and the optics are the same. This is quite different than space telescopes designed for IR imaging, which typically use special optics and detectors to image out to many micrometers, which means they are imaging thermal emissions from cool objects, not the hot sources that the HST camera is designed for.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
johnnydeep
Captain
Posts: 1592
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by johnnydeep » Sun Mar 07, 2021 6:26 pm

Chris Peterson wrote: Sun Mar 07, 2021 6:21 pm
johnnydeep wrote: Sun Mar 07, 2021 5:40 pm This is a very cool (or warm!) image. I see there's a detailed page link I still need to read all about Hubble imaging (namely, https://asd.gsfc.nasa.gov/blueshift/ind ... lse-color/), but can someone give the the executive summary of what has to change in Hubble for it to capture infra-red as opposed to visible light? Is it just swapping a different filter in place, or is there also a different sensor that is more sensitive to infrared? Obviously, the mirror itself can't change!
It is unfortunate that the filter details aren't provided. That said, "infrared" covers a very broad range. The IR that the HST can capture is pretty much the same optically as visible light. Its wavelengths are what can be detected by an ordinary silicon detector, which falls off rapidly above 1.5 micrometers. That is shorter than thermal IR. So yes... it's just a question of choosing an IR-pass filter in place of a visible light filter. The camera and the optics are the same. This is quite different than space telescopes designed for IR imaging, which typically use special optics and detectors to image out to many micrometers, which means they are imaging thermal emissions from cool objects, not the hot sources that the HST camera is designed for.
Thanks.
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."

User avatar
Ann
4725 Å
Posts: 12350
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by Ann » Sun Mar 07, 2021 7:06 pm

johnnydeep wrote: Sun Mar 07, 2021 5:40 pm This is a very cool (or warm!) image. I see there's a detailed page link I still need to read all about Hubble imaging (namely, https://asd.gsfc.nasa.gov/blueshift/ind ... lse-color/), but can someone give the the executive summary of what has to change in Hubble for it to capture infra-red as opposed to visible light? Is it just swapping a different filter in place, or is there also a different sensor that is more sensitive to infrared? Obviously, the mirror itself can't change!

Here you can see two pictures of the Eagle Nebula, where the infrared wavelengths are shown.

Ann
Color Commentator

User avatar
johnnydeep
Captain
Posts: 1592
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by johnnydeep » Sun Mar 07, 2021 9:55 pm

Ann wrote: Sun Mar 07, 2021 7:06 pm
johnnydeep wrote: Sun Mar 07, 2021 5:40 pm This is a very cool (or warm!) image. I see there's a detailed page link I still need to read all about Hubble imaging (namely, https://asd.gsfc.nasa.gov/blueshift/ind ... lse-color/), but can someone give the the executive summary of what has to change in Hubble for it to capture infra-red as opposed to visible light? Is it just swapping a different filter in place, or is there also a different sensor that is more sensitive to infrared? Obviously, the mirror itself can't change!

Here you can see two pictures of the Eagle Nebula, where the infrared wavelengths are shown.

Ann
Nice pics. For reference, IRAC is the InfraRed Array Camera on the Spitzer space telescope (https://en.wikipedia.org/wiki/Infrared_Array_Camera), and MIPS is the Multiband Imaging Photometer for Spitzer (https://www.as.arizona.edu/mips)
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."

User avatar
alter-ego
Serendipitous Sleuthhound
Posts: 1061
Joined: Mon Apr 21, 2008 4:51 am
Location: Redmond, WA

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by alter-ego » Mon Mar 08, 2021 2:01 am

Chris Peterson wrote: Sun Mar 07, 2021 6:21 pm
johnnydeep wrote: Sun Mar 07, 2021 5:40 pm This is a very cool (or warm!) image. I see there's a detailed page link I still need to read all about Hubble imaging (namely, https://asd.gsfc.nasa.gov/blueshift/ind ... lse-color/), but can someone give the the executive summary of what has to change in Hubble for it to capture infra-red as opposed to visible light? Is it just swapping a different filter in place, or is there also a different sensor that is more sensitive to infrared? Obviously, the mirror itself can't change!
It is unfortunate that the filter details aren't provided. That said, "infrared" covers a very broad range. The IR that the HST can capture is pretty much the same optically as visible light. Its wavelengths are what can be detected by an ordinary silicon detector, which falls off rapidly above 1.5 micrometers. That is shorter than thermal IR. So yes... it's just a question of choosing an IR-pass filter in place of a visible light filter. The camera and the optics are the same. This is quite different than space telescopes designed for IR imaging, which typically use special optics and detectors to image out to many micrometers, which means they are imaging thermal emissions from cool objects, not the hot sources that the HST camera is designed for.
The NIR image was capture by the WFC3 in 2014. This camera has a relatively high efficiency over a wide spectral range: 200nm → 1700nm, where 200nm to 1000 is covered by the Si CCD sensor, and IR channel detector is optimized for ~800nm → 1700nm. Much over 1.2um, Si detectors become transparent and not enough is absorbed for useful photon detection. Using an Si array, I've profiled laser beams out to ~1.2um maximum where sensitivity is exceedingly low. When I saw the listed WFC3 spectral range, I suspected there was either a different or additional sensor used.
HST Documentation - Optical Design and Detectors
WFC3 uses two different types of detectors. The UVIS channel uses two butted 4096 × 2051 thinned, back-illuminated e2v Ltd. (formerly Marconi) CCD detectors to support imaging between 200 and 1000 nm. The IR channel uses a 1024 × 1024 Teledyne (formerly Rockwell Scientific) HgCdTe detector array, with the central 1014 × 1014 pixels useful for imaging, and covering the near-infrared between 800 and 1700 nm.

The primary characteristics of the two channels are summarized in Table 2.1.
WFC3 Detector .jpg
You do not have the required permissions to view the files attached to this post.
A pessimist is nothing more than an experienced optimist

User avatar
johnnydeep
Captain
Posts: 1592
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Pillars of the Eagle Nebula in Infrared (2021 Mar 07)

Post by johnnydeep » Mon Mar 08, 2021 2:40 pm

alter-ego wrote: Mon Mar 08, 2021 2:01 am
Chris Peterson wrote: Sun Mar 07, 2021 6:21 pm
johnnydeep wrote: Sun Mar 07, 2021 5:40 pm This is a very cool (or warm!) image. I see there's a detailed page link I still need to read all about Hubble imaging (namely, https://asd.gsfc.nasa.gov/blueshift/ind ... lse-color/), but can someone give the the executive summary of what has to change in Hubble for it to capture infra-red as opposed to visible light? Is it just swapping a different filter in place, or is there also a different sensor that is more sensitive to infrared? Obviously, the mirror itself can't change!
It is unfortunate that the filter details aren't provided. That said, "infrared" covers a very broad range. The IR that the HST can capture is pretty much the same optically as visible light. Its wavelengths are what can be detected by an ordinary silicon detector, which falls off rapidly above 1.5 micrometers. That is shorter than thermal IR. So yes... it's just a question of choosing an IR-pass filter in place of a visible light filter. The camera and the optics are the same. This is quite different than space telescopes designed for IR imaging, which typically use special optics and detectors to image out to many micrometers, which means they are imaging thermal emissions from cool objects, not the hot sources that the HST camera is designed for.
The NIR image was capture by the WFC3 in 2014. This camera has a relatively high efficiency over a wide spectral range: 200nm → 1700nm, where 200nm to 1000 is covered by the Si CCD sensor, and IR channel detector is optimized for ~800nm → 1700nm. Much over 1.2um, Si detectors become transparent and not enough is absorbed for useful photon detection. Using an Si array, I've profiled laser beams out to ~1.2um maximum where sensitivity is exceedingly low. When I saw the listed WFC3 spectral range, I suspected there was either a different or additional sensor used.
HST Documentation - Optical Design and Detectors
WFC3 uses two different types of detectors. The UVIS channel uses two butted 4096 × 2051 thinned, back-illuminated e2v Ltd. (formerly Marconi) CCD detectors to support imaging between 200 and 1000 nm. The IR channel uses a 1024 × 1024 Teledyne (formerly Rockwell Scientific) HgCdTe detector array, with the central 1014 × 1014 pixels useful for imaging, and covering the near-infrared between 800 and 1700 nm.

The primary characteristics of the two channels are summarized in Table 2.1.

WFC3 Detector .jpg
This is great info - thanks!
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."