Elliptical galaxy IC 2006 PHY1107Astronomy 2 Faculty of Health, Engineering and Sciences Assessment...

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Elliptical galaxy IC 2006 PHY1107Astronomy 2 Faculty of Health, Engineering and Sciences Assessment 1 - Report Information Semester 2, 2017  Distributed byThe University of Southern Queensland Toowoomba, Queensland 4350 Australia http:www.usq.edu.au© University of Southern Queensland, 2017Copyrighted materials reproduced herein are used under the provisions of the Copyright Act 1968 as amended, or as a result of application to the copyright owner.No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, mechanical, photocopying, ecording or otherwise without prior permission.http:www.usq.edu.au  Contents Assessment 1 – Report ............................................................ XXXXXXXXXX1 Introduction ........................................................................ XXXXXXXXXX1 Purpose .............................................................................. XXXXXXXXXX1 Workload ............................................................................ XXXXXXXXXX1 Word Count ......................................................................... XXXXXXXXXX1 Weighting ............................................................................ XXXXXXXXXX2 Referencing and Plagiarism .................................................... XXXXXXXXXX2 Submission .......................................................................... XXXXXXXXXX2 Late Penalties ...................................................................... XXXXXXXXXX3 Assessment 1 - Report Brief ..................................................... XXXXXXXXXX4 Report Structure/Format .......................................................... XXXXXXXXXX9 Report Presentation Considerations ......................................... XXXXXXXXXX12   PHY1107 – Astronomy 2   Assessment Information Page 1 of 12  Assessment 1 – Report  Weight  20% Due Date  11:55pm 22 September 2017 (AEST) Introduction This Assessment writing task in this course relates to a scientific investigation and is designed to test your knowledge as well as develop your technical writing skills.  The Assessment is a Report, and needs to be clear, concise and well structured. Typically a report is aimed at a particular audience, in this case, a scientific audience, and should have a clearly structured format with suitable sections and headings so that the information is easy to understand, easy to locate and follow. The key to writing an effective report is to allocate time for planning and preparation and this will make the report writing much easier. For this Report, you are provided with a report ‘ief’ and aim that outlines the purpose of the investigation. The report outline also gives specific requirements for your documentation format/structure. The following pages goes through the specific information required to undertake this Report with respect to requirements from the course, how the Report will be marked, and the outline of the Report itself. Please make sure that you read all of the information contained in this document to ensure that you are aware of all of the requirements for this Assessment task. Purpose The Assignment is design to test your understanding of some of the concepts introduced in this course to date, and develop your skills in using the scientific method. Workload You can expect to spend approximately 24 hours on this assessment task. This includes the time needed to perform the necessary reading, planning and writing. Word Count Maximum 2500 words (excluding title page; table of content; figures; tables; and eference list)    PHY1107 – Astronomy 2   Assessment Information Page 2 of 12  Weighting This assessment comprises 20% of the course weighting. For calculation purposes this report will be marked out of a total of 20 marks as follows:   Weighting Mark out of Abstract 10% 2 Introduction 20% 4 Method 10% 2 Results  20% 4 Discussions 20% 4 Conclusions 10% 2 Presentation & References 10% 2 TOTAL MARKS 100% 20Referencing and Plagiarism The Report will need to include referencing using the Harvard AGPS system ONLY, and students are advised to take care to reference their work properly so as to avoid the risk of being accused of plagiarism. Learn more about how to eference your work using USQ’s referencing and plagiarism web pages:  https:www.usq.edu.au/liaryeferencing When using references, present the Report in your own words and incorporate quotations sparingly at most. Please also heed the USQ information concerning plagiarism: http:www.usq.edu.au/liaryeferencing/what-is-plagiarism Submission Assignments are to be submitted electronically, using the link provided on StudyDesk. Marked assignments will be returned via the StudyDesk grades and feedback system. Please use *.doc, *.docx, *.pdf format only to submit your assignment. Please use the naming convention: PHY1107_REPORT-LastName.pdf where: LastName is your last (family) name.Note: Emailed or printed work sent by post will not be accepted. https:www.usq.edu.au/liaryeferencinghttp:www.usq.edu.au/liaryeferencing/what-is-plagiarism  PHY1107 – Astronomy 2   Assessment Information Page 3 of 12  Late Penalties Requests for extensions generally will not be considered after the due date for this assessment, and study workload and work commitments are not usually considered a valid reason for lateness. Extensions of more than one week are usually not given as this increases the marking turnaround time and so disadvantages on-time students. Penalties may apply to late submissions as outlined in the USQ Assessment Procedure and the course specifications. For more detailed information regarding USQ’s policy of assessment submission, please see the below link: USQ Assessment Procedurehttp:policy.usq.edu.au/documents/14749PL  PHY1107 – Astronomy 2   Assessment Information Page

David · Accepted Answer

Galaxy Classification 
Introduction: 
The universe is full of various galaxies of different shapes, types and sizes. Thus to know how the universe 
itself evolved over time , about its structure,, how galaxies were formed , how stars are formed and how they die 
and other numerous questions there is need for investigation and study using special techniques. The present 
understanding of the cosmos is basically based on the chain or series of techniques, in which each link forms 
from  the links in the chain preceding to it, including supernovae as “standard candles” ( a kind of ladder ), thus 
the technique of period-luminosity relation of Cepheid variables is a way used to establish an extragalactic 
distance scale for far away galaxies . Thus the lives of all the galaxies are indeed connected with the evolution 
and structure of the universe, this is the reason that the study of various galaxies is a part of cosmology (Galaxy, 
2017)
Hubble’s Galaxy Classification system 
Edwin Hubble developed a Galaxy classification scheme in year 1926. This classification scheme or sequence is 
morphological in nature. He classified galaxies into four main types, namely Elliptical, Spiral, Barred Spiral and 
Irregular. Out of these four, three type of galaxies ( Elliptical, Spiral, Barred Spiral) are presented in form of  
“Tuning Fork” diagram, due to their shapes in which they are represented traditionally (Van Den Bergh, S., 
1976)
          Figure 1 : The Hubble Classification scheme of galaxies : Tuning fork diagram 
 (  http://astronomy.swin.edu.au/cosmos/H/Hubble+Classification)
http://astronomy.swin.edu.au/cosmos/H/Hubble+Classification
 
Why classify far away Galaxies 
With the advancement in Science and Technology, the question about our Universe, its origin and existence 
have made many scientist and astronomers across the globe to understand all the process occurring in the 
universe and how it has evolved over the period of time. 
Gathering the data, there are about 200, 000 images of galaxies between 800 million to 4 billion light years 
away, which are to be classified . These far off galaxies are key source of past , as comparing these galaxies can 
give an insight of how galaxy evolution has changed over time, different processes and interaction occurred 
between galaxies . Thus this information can change our fundamental understanding of dark matter as well as 
dark energy . (Galaxy, 2017) 
The process which is responsible for  the galaxy growth have changed from time to time as what astronomers 
believes, thus right from the Big Bang,  lots of merging, collisions, violet explosions have given birth to 
distorted asymmetrical shaped galaxies. As per investigations, the mergers of old and new galaxies were a 
dominant process during the early years, but now gas accretion is common now, which has given birth to the 
formation of spiral arms, thus providing in depth information about the mergers, gas accretion, spiral arm 
formation and other features of getting a more ordered system of galaxies . 
How Shape and Size of galaxies help to get insight of Universe 
With help of investigation , data collected and citizen scientists, the astronomers are now in position  to build 
statistics about in depth information about galaxies like how many galaxies have bars or spiral arms or bulges, 
how many are in state of merging , how many are smooth, how many galaxies are home to ancient starts. 
Thus with the help of these statistics, a system or model focusing on the evolution of entire galaxy system in the 
universe can be build and studied.  (Van Den Bergh, S., 1976)
Let us discuss these types of galaxies in detail 
1) Elliptical Galaxies :  Elliptical galaxies are rounder and redder as compared to other types of galaxies 
and contain comparatively lesser cool gas as well as dust particles. 
These galaxies were given numbers from 0 to 7 by Hubble, thus are labelled from E0 to E7 , which 
descriminate the ellipticity of a particular galaxy, “E0” being round in shape while “E7” is almost cigar 
shaped, the most elliptic of all. The E0 type of galaxies are situated at the far left corner of the tuning 
fork model while E7 type are at the right handle of tuning fork (Nova Celestia, 2017). Thus, their global 
properties like projected velocity dispersion, luminosity, radius etc forms a two-dimensional group. 
(Djorgovski, S. and Davis, M., 1987) 
Hubble’s elliptical galaxies are classified as per ellipticity of the galaxy which is given by  
E = 10 x (1 – x/y) 
Here y= semi-major axis and x = semi-minor axis of the ellipse.  
Thus, E0 are delibrated as “early type” ellipticals ( a spherical galaxy) while E7 are delibrated as “late type” 
(most flattened ) 
Elliptical galaxies are the most massive form of galaxies in the entire universe. This is due to the fact that they 
contain about hundreds to thousands of galaxies, all confined by gravity. The stars inside have random orbit 
unlike other galaxies. An example of Elliptical galaxy is Messier 87.
2) Lenticular galaxies:
These galaxies are located in between the elliptical and the spiral galaxies (in the transition zone) and are 
known as S0/SB0 galaxies as these are the galaxies that appear to have a spiral disc or prominent bulges but 
no visible spiral arms. S0 galaxies forms a bridge between elliptical and spiral galaxies.
3) Spiral galaxies :  
Spiral galaxies have spreaded  and curving arms like a whirlpool or even a pinwheel. These galaxies tend to 
collect in modest groups which contain upto many dozen galaxies. 
These spirals are divided into two subgroups, according to the tightness of the arms, size of the nucleus and 
how the core is shaped. On the basis of tightness of arms and size of nucleus these galaxies were assigned 
letters from “a” to “c” and are classified as Sa, Sb and Sc.  
As seen from the tuning fork diagram (Figure 1), in terms of arms , Sa spirals are the closest wound while Sc 
spirals are the most spreaded or open wound. In terms of nucleus , Sa spirals have the largest nucleus while the 
Sc spirals have the smallest nucleus. (Spacetelescope, 2017) 
Also if we have a close look at the sizes of the round central regions in the sprials which are known as bulges,

Elliptical galaxy IC 2006 PHY1107 Astronomy 2 Faculty of Health, Engineering and Sciences Assessment 1 - Report Information Semester 2, 2017 Distributed by The University of Southern Queensland...

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