THE INTENSITY PROFILE OF THE SOLAR SUPERGRANULATION

Journal Article · Thu Dec 10 04:00:00 EST 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/707/1/67· OSTI ID:21389331

Goldbaum, Nathan ^[1]; Rast, Mark P ^[2]; Ermolli, Ilaria ^[3]; Summer Sands, J ^[4]; Berrilli, Francesco ^[5]

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1. Laboratory for Atmospheric and Space Physics, Department of Physics, University of Colorado, Boulder, CO 80309 (United States)
2. Laboratory for Atmospheric and Space Physics, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States)
3. INAF-Osservatorio Astronomico di Roma, Via di Frascati, 33, I-00040 Monte Porzio (Italy)
4. SOARS and the High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)
5. Dipartimento di Fisica, Universita di Roma Tor Vergata, Viale della Ricerca Scientifica, 1, I-00133 Roma (Italy)

We have measured the average radial (cell center to network boundary) profile of the continuum intensity contrast associated with supergranular flows using data from the Precision Solar Photometric Telescope at the Mauna Loa Solar Observatory. After removing the contribution of the network flux elements by the application of masks based on Ca II K intensity and averaging over more than 10{sup 5} supergranular cells, we find a approx0.1% decrease in red and blue continuum intensity from the supergranular cell centers outward, corresponding to a approx1.0 K decrease in brightness temperature across the cells. The radial intensity profile may be caused either by the thermal signal associated with the supergranular flows or a variation in the packing density of unresolved magnetic flux elements. These are not unambiguously distinguished by the observations, and we raise the possibility that the network magnetic fields play an active role in supergranular scale selection by enhancing the radiative cooling of the deep photosphere at the cell boundaries.

• OSTI ID: 21389331
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 707; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ATMOSPHERES
BRIGHTNESS
COOLING
MAGNETIC FIELDS
MAGNETIC FLUX
MAIN SEQUENCE STARS
OPTICAL PROPERTIES
PHOTOSPHERE
PHYSICAL PROPERTIES
RADIATIVE COOLING
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR GRANULATION
STARS
STELLAR ACTIVITY
STELLAR ATMOSPHERES
SUN
TELESCOPES