Focus area: Galactic Motion NGC 891 Focus area: Galactic Motion Joshua Gross 7731058

NGC 891 (AKA UGC 1831, PGC 9031, Caldwell 23) RA: 2h 22m 33.4s (J2000) Dec: +42d 20’ 57” (J2000) Type: Unbarred spiral galaxy, viewed edge on Distance: 27.3 Mly Magnitude: 10.8 Surface Brightness: 14.6 mag/arcmin Angular Dimensions: 13.5’ x 2.5’ Physical size: 105,000 ly across Location: Andromeda constellation, part of the NGC 1023 local group and in turn part of Virgo super cluster Interesting Facts: This galaxy is how we would think the milky way appears when viewed edge on. Was chosen to be the first light image for Large binocular telescope in 2005. Because we can see NGC 891 edge on, an observer in that galaxy would not be able to see the milky way in the visible spectrum as the milky way would fall in NGC 891’s zone of avoidance NASA Extra Galactic Database (NED) "First Light Information". Large Binocular Telescope Observatory. 2008

NGC 891 Edge-on http://apod.nasa.gov/apod/ap131011.html

https://commons. wikimedia. org/wiki/File:NGC_891_Hubble_north_part https://commons.wikimedia.org/wiki/File:NGC_891_Hubble_north_part.jpg

At the Edge of NGC 891, http://apod.nasa.gov/apod/ap120526.html

Observing Session: Date: 03 Mar 16 Sunset: 1815 CST Astronomical Twilight: 2002 CST Moonset: 1227 CST Moon phase: Waxing crescent SQM: 16.13 @ 1901, 20.39 @ 2001, 20.46 @ 2101 Cloud Cover: 10% (thin layer at times) Seeing: average-below average Darkness: 5.6/6.0 Temperature: -10oC Humidity: 60% Pressure: 99.1 kPa Wind 12 km/h Issues finding original visual check star Almaak, used the star Mirphak instead When locating focus star a star field image was used to find the proper star Nearing end of data collection thin layer of cloud came in, obscuring images As well when lower in the sky near end of observations effects of light pollution and increased air mass distort images making the blurry

Reduced Image -data reduced using bias, dark, and flat frames -Used average z project

Same as previous image but used median z projection

Used blue lookup table - Able to resolve more of galaxy

-Used red LUT - Reduces some of the noise in image

-Sepia LUT -Image highlights dust band

-Thallium LUT Galaxy and major stars stand out Good contrast between luminous part of galaxy and dust bad good contrast between galaxy and background

Research and Focus Area Galaxy Motion Hubble Flow: Objects in deep space found to have Doppler shifted light that is shifted to red spectrum (red shift) This red shift increases proportional to distance and increases the further an object is from earth Recession Velocity = Ho x D (Ho = Hubble constant ~ 70 km/s/Mpc, D=distance) Attributed to Edwin Hubble but idea first derived in 1927 by Georges Lemaitre from general relativity. Hubble confirmed theory two years later and determined hubble constant more accurately Some Galaxies moving away faster the light because recession velocity caused by universal expansion Only true for galaxies outside local region, other factors such as motion within local group, cluster, super cluster have effect Hubble’s law http://www.astro.cornell.edu/academics/courses/astro201/hubble_law.html

Local Group 50+ galaxies and dwarf galaxies Milky Way and Andromeda are largest galaxies Motion dominated by gravity of these galaxies This structure scale is small enough to be out of the Hubble flow and galaxies are moving together here The cosmic distance scale, the local group http://imagine.gsfc.nasa.gov/features/cosmic/local_group_info.html

By Andrew Z. Colvin (Own work) [CC BY-SA 3. 0 (http://creativecommons By Andrew Z. Colvin (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons

Virgo Super cluster 100+ galaxy groupings and clusters 33 mpc across One of millions of super clusters Hubble flow is apparent between galaxy groupings but there are other forces at work in galactic motion NGC 1023 grouping which contains NGC 891 is located in this region New study shows Virgo to only be a lobe of a much larger Laniakea SC arXiv:0906.2540v1 [astro-ph.CO] 10 facts about the milky way, Williams, M. 2014, Universe Today

Richard Powell CC BY-SA 2. 5 https://en. wikipedia

Laniakea Super Cluster -100,000+ galaxies -160 mpc across -comprised of four major parts that were seen as separate super clusters before(Virgo, Hydra-Centarus, Pavo-Indus, Southern super clusters) 2014 study sets new criteria for designating super clusters Based on peculiar motion of galaxy clusters(motion predicted by hubble flow plus a small velocity due to flow within cluster envirnment) Found to be a bulk flow of galaxies towards area near Noma termed the great attractor R. Brent Tully, Hélène Courtois, Yehuda Hoffman, Daniel Pomarède. The Laniakea supercluster of galaxies. Nature, 2014; 513 (7516): 71 DOI: 10.1038/nature13674

Laniakea Supercluster of Galaxies, arXiv:1409.0880v1 [astro-ph.CO]

The Great Attractor Gravitational anomaly in intergalactic space with a mass ten’s of thousand’s times the milky way Only viewed in x-ray as it is in our zone of avoidance Defines our super cluster as it is what dominates the peculiar velocity of galaxy groupings in our super cluster No clear picture of what it actually is made of or what is causing it arXiv:1409.0880v1 [astro-ph.CO]

Research Paper -Discusses how they are proposing the definition of a super cluster to be Galaxy’s group together in clusters that in turn bunch along filaments that trace out the boundaries of areas absent of galaxies called voids Explains that the Laniakea super cluster is like a water shed with the peculiar flow of galaxies flowing towards a common point of attraction(the great attractor) The water shed or area of influence for these attractors determine the boundaries of the super cluster not the location of the galaxy group arXiv:1409.0880v1 [astro-ph.CO]

arXiv:1409.0880v1 [astro-ph.CO]

Conclusion Multiple factors at different levels affect galactic motion beyond Hubble flow NGC 891 is not in our local group but is in our super cluster Hubble flow still dominates over all galactic motion Our galactic neighbourhood has recently gotten a whole lot bigger

Questions?

Refrences Laniakea Supercluster of Galaxies, arXiv:1409.0880v1 [astro-ph.CO] NASA Extra Galactic Database (NED) "First Light Information". Large Binocular Telescope Observatory. 2008 NGC 891 Edge-on http://apod.nasa.gov/apod/ap131011.html https://commons.wikimedia.org/wiki/File:NGC_891_Hubble_north_part.jpg At the Edge of NGC 891, http://apod.nasa.gov/apod/ap120526.html Hubble’s law http://www.astro.cornell.edu/academics/courses/astro201/hubble_law.html The cosmic distance scale, the local group http://imagine.gsfc.nasa.gov/features/cosmic/local_group_info.html By Andrew Z. Colvin (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons arXiv:0906.2540v1 [astro-ph.CO] 10 facts about the milky way, Williams, M. 2014, Universe Today Richard Powell CC BY-SA 2.5 https://en.wikipedia.org/wiki/File:Virgosupercluster_atlasoftheuniverse.gif#/media/File:Virgosupercluster_atlasoftheuniverse.gif R. Brent Tully, Hélène Courtois, Yehuda Hoffman, Daniel Pomarède. The Laniakea supercluster of galaxies. Nature, 2014; 513 (7516): 71 DOI: 10.1038/nature13674