Sighting forbidden light

Esahubble_potw2351a_1024

esahubble_potw2351a December 18th, 2023

Credit: ESA/Hubble & NASA, C. Kilpatrick

This whirling image features a bright spiral galaxy known as MCG-01-24-014, which is located about 275 million light-years from Earth. In addition to being a well-defined spiral galaxy, MCG-01-24-014 has an extremely energetic core, known as an active galactic nucleus (AGN), so it is referred to as an active galaxy. Even more specifically, it is categorised as a Type-2 Seyfert galaxy. Seyfert galaxies host one of the most common subclasses of AGN, alongside quasars. Whilst the precise categorisation of AGNs is nuanced, Seyfert galaxies tend to be relatively nearby ones where the host galaxy remains plainly detectable alongside its central AGN, while quasars are invariably very distant AGNs whose incredible luminosities outshine their host galaxies. There are further subclasses of both Seyfert galaxies and quasars. In the case of Seyfert galaxies, the predominant subcategories are Type-1 and Type-2. These are differentiated from one another by their spectra — the pattern that results when light is split into its constituent wavelengths — where the spectral lines that Type-2 Seyfert galaxies emit are particularly associated with specific so-called ‘forbidden’ emission. To understand why emitted light from a galaxy could be considered forbidden, it helps to understand why spectra exist in the first place. Spectra look the way they do because certain atoms and molecules will absorb and emit light very reliably at very specific wavelengths. The reason for this is quantum physics: electrons (the tiny particles that orbit the nuclei of atoms and molecules) can only exist at very specific energies, and therefore electrons can only lose or gain very specific amounts of energy. These very specific amounts of energy correspond to certain light wavelengths being absorbed or emitted. Forbidden emission lines, therefore, are spectral emission lines that should not exist according to certain rules of quantum physics. But quantum physics is complex, and some of the rules used to predict it use assumptions that suit laboratory conditions here on Earth. Under those rules, this emission is ‘forbidden’ — so improbable that it’s disregarded. But in space, in the midst of an incredibly energetic galactic core, those assumptions don’t hold anymore, and the ‘forbidden’ light gets a chance to shine out towards us. [Image Description: A spiral galaxy. It appears to be almost circular and seen face-on, with two prominent spiral arms winding out from a glowing core. It is centred in the frame as if a portrait. Most of the background is black, with only tiny, distant galaxies, but there are two large bright stars in the foreground, one blue and one red, directly above the galaxy.] Links Pan: Sighting forbidden light

Provider: Hubble Space Telescope | ESA

Image Source: https://esahubble.org/images/potw2351a/

Curator: ESA/Hubble, Baltimore, MD, United States

Image Use Policy: Creative Commons Attribution 4.0 International License

Image Details

Image Type
Observation
Object Name
MCG-01-24-014
Esahubble_potw2351a_128
 

Position Details

Position (ICRS)
RA = 9h 24m 26.5s
DEC = -6° 34’ 54.3”
Orientation
North is 124.8° CCW
Field of View
2.3 x 2.9 arcminutes
Constellation
Hydra

Color Mapping

  Telescope Spectral Band Wavelength
Blue Hubble (ACS) Optical (V) 555.0 nm
Green Hubble (ACS) Optical (V) 555.0 nm
Green Hubble (ACS) Optical (I) 814.0 nm
Red Hubble (ACS) Optical (I) 814.0 nm
Spectrum_base
Blue
Green
Green
Red
Esahubble_potw2351a_1280
×
ID
potw2351a
Subject Category
Subject Name
MCG-01-24-014
Credits
ESA/Hubble & NASA, C. Kilpatrick
Release Date
2023-12-18T06:00:00
Lightyears
Redshift
Reference Url
https://esahubble.org/images/potw2351a/
Type
Observation
Image Quality
Distance Notes
Facility
Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope, Hubble Space Telescope
Instrument
ACS, ACS, ACS, ACS
Color Assignment
Blue, Green, Green, Red
Band
Optical, Optical, Optical, Optical
Bandpass
V, V, I, I
Central Wavelength
555, 555, 814, 814
Start Time
Integration Time
Dataset ID
None, None, None, None
Notes
Coordinate Frame
ICRS
Equinox
J2000
Reference Value
141.1103283166192, -6.581759727400251
Reference Dimension
2771.0, 3464.0
Reference Pixel
1385.5, 1732.0
Scale
-1.388073174744368e-05, 1.388073174744368e-05
Rotation
124.76000000000012
Coordinate System Projection:
TAN
Quality
Full
FITS Header
Notes
Creator (Curator)
ESA/Hubble
URL
https://esahubble.org
Name
Email
Telephone
Address
ESA Office, Space Telescope Science Institute, 3700 San Martin Dr
City
Baltimore
State/Province
MD
Postal Code
21218
Country
United States
Rights
Creative Commons Attribution 4.0 International License
Publisher
ESA/Hubble
Publisher ID
esahubble
Resource ID
potw2351a
Metadata Date
2023-12-12T16:58:32+01:00
Metadata Version
1.1
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Detailed color mapping information coming soon...

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There is no distance meta data in this image.

 

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