<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-20T07:56:35Z</responseDate><request verb="GetRecord" identifier="oai:dspace.mit.edu:1721.1/40918" metadataPrefix="dim">https://dspace.mit.edu/server/oai/request</request><GetRecord><record><header><identifier>oai:dspace.mit.edu:1721.1/40918</identifier><datestamp>2022-01-13T07:54:41Z</datestamp><setSpec>com_1721.1_7582</setSpec><setSpec>com_1721.1_7581</setSpec><setSpec>col_1721.1_131024</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" qualifier="advisor" lang="en_US">Saul Rappaport and Al Levine.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="author" lang="en_US">Jones, Tucker Anthony</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="other" lang="en_US">Massachusetts Institute of Technology. Dept. of Physics.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="department">Massachusetts Institute of Technology. Department of Physics</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="accessioned">2008-03-27T18:23:15Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="available">2008-03-27T18:23:15Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="copyright" lang="en_US">2007</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued" lang="en_US">2007</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">http://hdl.handle.net/1721.1/40918</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="oclc" lang="en_US">212377369</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2007.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Includes bibliographical references (p. 77-81).</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en_US">I describe the detection of 201 highly significant dips in the count rate of Sco X-1 from a search of some 500 ks of archival RXTE PCA data, which could be caused by TNO occultations. I show that most of these dips are correlated with particle showers in the PCA, suggesting that the dips in count rate result from large amounts of charge built up in the detectors. From the distribution of particle counts in the PCA and examination of asymmetry in individual dip profiles, I establish that at most ~ 6 of these dip events can be caused by occultations. This gives an upper limit on the cumulative TNO size distribution for > 20 m radius. I also derive a model lightcurve for occultations of Sco X-1 from diffraction theory, and use this model to predict properties of an ensemble of occultation events. Implications for future work are discussed.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="statementofresponsibility" lang="en_US">by Tucker Anthony Jones.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="degree" lang="en_US">S.B.</dim:field>
   <dim:field mdschema="dc" element="format" qualifier="extent" lang="en_US">81 p.</dim:field>
   <dim:field mdschema="dc" element="language" qualifier="iso" lang="en_US">eng</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="en_US">Massachusetts Institute of Technology</dim:field>
   <dim:field mdschema="dc" element="rights" lang="en_US">M.I.T. theses are protected by &#xd;
copyright. They may be viewed from this source for any purpose, but &#xd;
reproduction or distribution in any format is prohibited without written &#xd;
permission. See provided URL for inquiries about permission.</dim:field>
   <dim:field mdschema="dc" element="rights" qualifier="uri" lang="en_US">http://dspace.mit.edu/handle/1721.1/7582</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en_US">Physics.</dim:field>
   <dim:field mdschema="dc" element="title" lang="en_US">An upper limit on the abundance of small trans-Neptunian objects from X-ray occultations</dim:field>
   <dim:field mdschema="dc" element="type" lang="en_US">Thesis</dim:field>
   <dim:field mdschema="dc" element="format" qualifier="mimetype">application/pdf</dim:field>
   <dim:field mdschema="dspace" element="authorsordered">false</dim:field>
   <dim:field mdschema="dspace" element="entity" qualifier="type">Publication</dim:field>
   <dim:field mdschema="others" element="access-status">unknown</dim:field>
   <dim:field mdschema="others" element="access-status">unknown</dim:field>
   <dim:field mdschema="cerif" element="openaire" authority="" confidence="-1">&lt;Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="9b98b585-6a67-4587-95c7-f61f5a0517c1">
	&lt;Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843&lt;/Type>
	&lt;Language>eng&lt;/Language>
   	&lt;Title>An upper limit on the abundance of small trans-Neptunian objects from X-ray occultations&lt;/Title>
   	&lt;PublishedIn>
    	&lt;Publication>
      	&lt;/Publication>
   	&lt;/PublishedIn>
   	&lt;PublicationDate>2007&lt;/PublicationDate>
   	&lt;Authors>
      	&lt;Author>
        	&lt;DisplayName>Jones, Tucker Anthony&lt;/DisplayName>
         	&lt;Affiliation>
         		&lt;OrgUnit>
         		&lt;/OrgUnit>
         	&lt;/Affiliation>
      	&lt;/Author>
	&lt;/Authors>
   	&lt;Editors>
	&lt;/Editors>
    &lt;Publishers>
        &lt;Publisher>
            &lt;DisplayName>Massachusetts Institute of Technology&lt;/DisplayName>
            &lt;OrgUnit />
        &lt;/Publisher>
    &lt;/Publishers>
    &lt;License>http://dspace.mit.edu/handle/1721.1/7582&lt;/License>
    &lt;Keyword>Physics.&lt;/Keyword>
   	&lt;Abstract>I describe the detection of 201 highly significant dips in the count rate of Sco X-1 from a search of some 500 ks of archival RXTE PCA data, which could be caused by TNO occultations. I show that most of these dips are correlated with particle showers in the PCA, suggesting that the dips in count rate result from large amounts of charge built up in the detectors. From the distribution of particle counts in the PCA and examination of asymmetry in individual dip profiles, I establish that at most ~ 6 of these dip events can be caused by occultations. This gives an upper limit on the cumulative TNO size distribution for &amp;gt; 20 m radius. I also derive a model lightcurve for occultations of Sco X-1 from diffraction theory, and use this model to predict properties of an ensemble of occultation events. Implications for future work are discussed.&lt;/Abstract>
	&lt;Access xmlns="http://purl.org/coar/access_right" 
    >
    &lt;/Access>
&lt;/Publication>
</dim:field>
</dim:dim>
</metadata></record></GetRecord></OAI-PMH>