Observatory  Update  –  Dec.  2010  

Dennis  Crabtree  NRC-­‐HIA  

Data  Sources  

•  List  of  papers  retrieved  from  observatory  websites  or  obtained  from  observatory  librarians  (Thanks!)  

•  No  checking  of  these  lists  –  trust  observatory  judgment  on  what  consNtutes  an  observatory  paper  –  “A  paper  based  on  data  acquired  at  the  observatory”  

•  Many  papers  based  on  data  obtained  from  more  than  one  observatory  –  Give  each  observatory  full  credit  for  these  papers  

•  CitaNons  for  each  paper  retrieved  from  ADS  –  Need  to  wait  at  least  a  year  since  publicaNon  of  paper  before  citaNon  count  is  meaningful  

–  Raw  citaNon  counts  need  to  be  adjusted  if  comparing  papers  of  different  ages  

•  Study  includes:  CFHT,  ESO  3.6,  Gemini,  HST,  JCMT,  Keck,  Magellan,  Mayall,  Subaru,  UKIRT,  VLT  

#  of  Papers  per  Telescope  

0

20

40

60

80

100

120

140

160

180

2005 2006 2007 2008 2009

CFHT

ESO3.6mGemini

HST

JCMTKeck

MagellanMayall

SubaruUKIRT

VLT

HST  numbers  divided  by  7  to  fit  on  same  scale!  

Papers’  use  of  telescope  data  

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

1 2 3 4 5 6

%

of

Papers

#  of  Telescopes

Papers  Claimed  by  Multiple  Telescopes

CFHT

ESO3p6

Gemini

HST

JCMT

Keck

Magellan

Mayall

Subaru

UKIRT

VLT

2004-­‐2009  Papers  

E.g.  –  71%  of  JCMT  papers  based  solely  on  JCMT  data  while  15%  are  based  on  data  from  JCMT  and  one  other  telescope  

Impact  Metric  

•  CitaNons  counts  grow  as  a  paper  ages  –  Peak  citaNon/count/year  occurs  ~  2-­‐3  years  ader  publicaNon  

•  Need  a  standard  citaNon  (impact)  metric  –  Allows  comparison  of  papers  of  different  ages  –  Common  treatment  of  impact  for  the  complete  sample  

•  Use  the  median  cita7on  count  for  AJ  papers  of  a  given  year  as  a  standard  measure  

•  Impact  is  defined  as  the  raNo  of  the  citaNons  of  a  paper  to  the  median  #  of  citaNons  for  AJ  papers  of  the  same  year  

•  Using  ApJ  rather  AJ  would  simply  change  the  length  of  our  standard  measuring  sNck  (meter  –  yard)  

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

2005 2006 2007 2008 2009

Average

Impact

per

Paper

Year

Average  Impact  Per  Paper:  2005  -­‐ 2009  papers

CFHT

ESO3.6mGemini

HSTJCMT

Keck

MagellanMayall

NTTSubaru

UKIRTVLT

WIYN

1.00

1.50

2.00

2.50

3.00

3.50

4.00

2005 2006 2007 2008 2009

Median

Impact

per

Paper

Median  Impact  per  Paper:  2005-­‐2009   Papers

CFHT

ESO3p6Gemini

HSTJCMT

Keck

MagellanMayall

NTTSubaru

UKIRTVLT

WIYN

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

Very  Low Low Moderate High Very  High Extreme

%

of

Papers

Impact  Distribution  Function  (2005  -­‐ 2009  Papers)

CFHT

ESO3.6Gemini

HST

JCMTKeck

MagellanMayall

NTTSubaru

UKIRT

VLTWIYN