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J/ApJ/660/146       HE 1104-1805 differential light curves   (Poindexter+, 2007)
Mid-IR observations and a revised time delay for the gravitational lens system
quasar HE 1104-1805.
    Poindexter S., Morgan N., Kochanek C.S., Falco E.E.
   <Astrophys. J., 660, 146-151 (2007)>
   =2007ApJ...660..146P
ADC_Keywords: QSOs ; Photometry

Keywords: gravitational lensing - quasars: general -
          quasars: individual (HE 1104-1805)

Abstract:
    The mid-IR flux ratios FA/FB=2.84±0.06 of the two images of the
    gravitationally lensed quasar HE 1104-1805 show no wavelength
    dependence to within 3% across 3.6-8.0um, show no time dependence
    over 6 months, and agree with the broad emission-line flux ratios.
    This indicates that the mid-IR emission likely comes from scales large
    enough to be little affected by microlensing and that there is little
    differential extinction between the images. We measure a revised time
    delay between these two images of 152.2+2.8-3.0 (1sigma) days from
    R- and V-band data covering the years 1997-2006. This time delay
    indicates that the lens has an approximately flat rotation curve over
    scales of 1-2Re. We also observed uncorrelated variations of
    ∼0.05mag/yr, which we attribute to microlensing of the optical
    emission from the accretion disk. The optical colors have also changed
    significantly in the sense that image A is now redder than image B,
    rather than bluer, as it was in 1993.

Description:
    HE 1104-1805 was originally observed with HST by Lehar et al.
    (2000ApJ...536..584L), but we obtained deeper NICMOS NIC2 F160W (H
    band) observations as part of GO-9375 on 2003 December 17 (HJD
    2452990.9), with the aim of improving the lens galaxy astrometry and
    profile and studying the quasar host galaxy.
    We observed HE 1104-1805 with Spitzer and the Infrared Array Camera
    (IRAC) on 2005 June 15 and 2006 January 2 as part of Spitzer program
    20451.
Objects:
    -------------------------------------------------------
       RA   (2000)   DE      Designation(s)
    -------------------------------------------------------
    11 06 33.5   -18 21 24   HE 1104-1805 = QSO B1104-1805
    -------------------------------------------------------

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table3.dat        65      208   Light Curves for HE 1104-1805


Table 2: Relative astrometry and photometry for field reference stars
--------------------------------------------------------------------------------
   ID     oRA         oDE       DRmag          DJmag
         arcsec     arcsec        mag           mag
--------------------------------------------------------------------------------
   1      -3.4      -15.1        0               0
   2      31.8       -5.3    0.731±0.002     ---
   3     -45.7       23.8    0.604±0.002   0.653±0.009
   4      33.6      119.3   -0.003±0.003     ---
   5    -143.9      -64.4   -1.896±0.028     ---
--------------------------------------------------------------------------------
 Note: The positions are measured with respect to HE 1104-1805 image A. The
        magnitude differences are for the SMARTS R- and J-band data. For the
        SOAR data, only star 1 (set to unity) was available as a local
        reference star.

Byte-by-byte Description of file: table3.dat

   Bytes Format Units   Label   Explanations

   1- 11  F11.3 d       HJD     Heliocentric Julian Date
  13- 16  F4.2  ---     Rchi2   Reduced χ2
  18- 23  F6.3  mag     CompA   Relative image A magnitude (1)
  25- 29  F5.3  mag    e_CompA  Uncertainty in CompA (1)
  31- 36  F6.3  mag     CompB   Relative image B magnitude (1)
  38- 42  F5.3  mag    e_CompB  Uncertainty in CompB (1)
  44- 49  F6.3  mag     RStar   ?=0. Average magnitude difference of reference
                                 stars (2)
  51- 55  F5.3  mag    e_RStar  ? Uncertainty in RStar
  57- 62  A6    ---     Tel     [SMARTS SOAR] Telescope used
  64- 65  A2    ---     Filt    [BIJR HJKs] Filter used

Note (1): Relative to the local reference stars.

Note (2): Relative to the campaign mean. Values are 0 for the three
     SOAR data points because we have only one epoch of data.


History:
    From electronic version of the journal
(End)                  Greg Schwarz [AAS], Patricia Vannier [CDS]    04-Mar-2009