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Rudy Kokich
Virginia
06/09/2021

Equipment Details:

-Remote Takahashi TOA 150 x 1105mm, Paramount GT GEM

Post-processing Details:

-29 x 300 sec OSC, 15% and 25% area crop

-Software:
DSS, XnView, StarNet++, StarTools v 1.3 and 1.7,
Extragalactic Cosmological Calculator 2
https://www.cloudyni...download-links/

Image Details:

NGC 5364 (NGC 5317) and NGC 5363 Galaxy Group,Virgo

Annotated Image link
https://www.cloudynights.com/gallery/image/125908-ngc-5364-ngc-5317-and-ngc-5363-galaxy-groupvirgo-annotated/

NGC 5364, also catalogued as NGC 5317, is a "grand-design" spiral galaxy discovered by William Herschel in 1786. Its morphological classification of SA(rs)bc pec indicates an incomplete ring structure, loosely wound spiral arms, and a peculiar asymmetry of the galactic bulge and the spiral arms which is probably due to gravitational perturbation by its neighbors. The most likely cause is the nearby lenticular galaxy NGC 5360, although some sources suggest that the more distant NGC 5363 also shows evidence of gravitational interaction. Based on its redshift and apparent size and magnitude, NGC 5364 is about 57.4 million light years distant, and receding at 1,239 km/s due to the expansion of the Universe. It is approximately 93,000 LY in diameter, and half as bright as the Milky Way. Light blue floccules in the spiral arms are OB Associations, or immense clusters of large, very hot young stars. Hubble images of the galaxy also show numerous regions of hydrogen gas partially ionised by ultraviolet light from recently formed stars.

The other major galaxy in the image is NGC 5363, also discovered by William Herschel in 1784. As a fairly featureless lenticular galaxy, with a well developed nuclear bulge and a diffuse galactic disk, it is far less spectacular in the visible band than its grand-design spiral companion. However, in the infrared band, the galaxy displays two prominent lanes of cold dust which still retain evidence of a spiral structure and a central bar. The total mass of interstellar dust is about 100 times greater than expected from the total mass lost by evolved stars, which suggests an external origin. The detection of density shells within the galaxy as evidence of recent mergers confirms the hypothesis that the excess interstellar dust was acquired through accretion. Further, ultraviolet studies reveal the presence of young, hot stars born during star formation activity caused by a recent merger. Spectroscopic studies of the central region show evidence of an active galactic nucleus (AGN) of the LINER type, powered by the accretion disk of a central supermassive black hole (SMBH) with a mass of 375 million solar. The AGN is also a source of radio waves, indicating the precence of polar jets emanating from the central SMBH, generating synchrotron radiation. Thus, when studied throughout the electromagnetic spectrum, this apparently featureless galaxy tells a fascinating story. Based on measurable properties (redshift, apparent magnitude, and angular size), NGC 5363 is about 90,000 LY in diameter, and one third as bright as the Milky Way (much of its visible light is extincted by the dust). It lies at a distance of 57 million LY, receding at 1,129 km/s due to the expansion of the Universe. It is approximately 5 million LY distant from its spiral companion, NGC 5364, so it does not appear likely that either is tidaly deforming the other at present, though they are members of the same gravitationally bound galaxy cluster.

The other members within the photograph belonging to the NGC 5364 galaxy group are marked in light blue color on the annotated image, and their physical properties are described on the attached chart. The group belongs to the Virgo III Galaxy Group, which is itself the E part of the large Virgo Galaxy Cluster.
http://www.atlasoftheuniverse.com/galgrps/viriii.html

In the backround lie more remote galaxies at distances between 250 million and 1.5 billion LY. These are marked in green and yellow color on the annotated image, depending on their redshift. Included also are four quasars QSOs). The most distant of these is WISEA J135345.93+051305.4. Its redshift of 3.400 indicates that the light we are presently recording travelled for 11.8 billion years to reach us (lookback time, or light travel distance). When the light was emitted, the quasar was about 16,000 times brighter than the Milky Way, and was receding from the future location of our galaxy at 270,343 km/sec (redshift, apparent, or relativistic recession velocity). In the present epoch, its (comoving = proper) distance is around 22.4 billion LY, and it is receding at the superluminal proper recession velocity of 483,700 km/s. The quasar is presently located well beyond the cosmic event horizon, and the photons it is presently emitting can never reach us. It can be calculated that 99.73% of the light originally emitted was lost to "cosmological extinction", or literally diluted by the expansion of space through which it travelled.