ASTROPHISICAL QUANTITIES PROPAGATION RESEARCH OBJECT Propagation of properties extracted from the HyperLEDA catalog in the calculation of luminosities of galaxies. SUMMARY ___________________________________________ The scientific experiment represented by this research object pertains to the multi-wavelength study for a sample of the most isolated galaxies in the local universe. This study characterizes each galaxy of this sample through both the measurement of basic astrophysical properties: - The equatorial coordinates in J2000 epoch - The velocities in km/s (v) - The dust extinction coefficient (ag) - The axis ratio of the isophote 25 mag/arcsec2 (logr25) - The apparent total B magnitude (BT) - The morphological type (t) and the calculation of the more complex properties: - The distance in Mega parsecs (D) - The corrected apparent B magnitude (btc) - The optical luminosity in B-band (LB) Specifically, this research object is focused on the calculation of the intrinsic luminosity in the Johnson B-band, in order to achieve it the measurement or calculation of all those astrophysical properties is needed. All the data involved in the characterization of the sample are stored in a local relational MySQL database. To maintain up to date this database and to register all the updates properly is part of this scientific experiment. GET/CALCULATE THE ASTROPHISICAL PROPERTIES _______________________________________________ A group of properties are extracted from HyperLEDA database. HyperLEDA offers a web based query interface that, given the name of a galaxy, allows the retrieval of homogenized astrophysical data related with the physics and evolution of galaxies. The properties acquired from this service are: - The equatorial coordinates in J2000 epoch - The velocities in km/s (v) - The dust extinction coefficient (Ag) - The axis ratio of the isophote 25 mag/arcsec2 (logr25) - The apparent total B magnitude (BT) The morphological type of the galaxies are provided by our own group (AMIGA), and it is decided by the expert members of the group through visual inspection of images. CALCULATION OF THE DISTANCE (D) If the heliocentric velocity in km/s is lower than 1000, we consider the heliocentric velocity is affected by the random movements of the galaxy, so we can not calculate the distance. If the heliocentric velocity in km/s is higher than 1000: D=Vvir/H0 H0 is the Hubble constant, where a value of 75 km/s Mpc has been used Vvir is the heliocentric velocity of the galaxy measured in the reference system of the Virgo cluster: Vvir = vlg + 208 cos(theta) (theta angular distance between observed directio and Virgo center) vlg = v + 295 sin(al2) cos(ab2) - 79.1 cos(al2) cos(ab2) - 37.6 sin (ab2), where al2 and ab2 are the Galactic coordinates (longitude and latitude) and v the heliocentric velocity in km/s CALCULATION OF THE CORRECTED APPARENT B MAGNITUD (btc) btc = bt - ag - ai - ak(t).v/10000. ak(t), coefficient for the k-correction, is taken from de Vaucouleurs et al (1976, RC2 p33 rel.25) and v is the heliocentric velocity in km/s In practice ak(t), where t is the morphological type, is tabulated as follows: ak(-5)=0.15 ak(-4)=0.15 ak(-3)=0.15 ak(-2)=0.15 ak(-1)=0.15 ak(0)=0.15 ak(1)=0.125 ak(2)=0.100 ak(3)=0.075 ak(4)=0.065 ak(5)=0.055 ak(6)=0.045 ak(7)=0.035 ak(8)=0.025 ak(9)=0.015 ak(10)=0.005 When the heliocentric velocity is lower than 1000 km/s, the ak will be 0 ai = f (t, logr25) = -2.5log[k+(1-k)R*((2C(1+0.2/K2)-1)] * k is the bulge to disk ratio and depends on morphological type as follows: * k=0.754*10(-0.2*t), if k >1 then k=1 (Simien and de Vaucouleurs) * K2 is the coefficient dlogD/db (where D is the isophotal diameter at surface brightness b). It depends on the morphological type t as: * K2 = 0.12-0.007*t if t < 0 * K2 = 0.094 if t >= 0. * R = 10.**float(logr25) axis ratio derived from logr25 * C is defined as (dlogD/dlogR) and has the fixed value of 0.04 CALCULATION OF THE OPTICAL LUMINOSITY IN B-BAND (LB) LB = 2.0log10(D)+11.95-0.4*btc UPDATE THE DATABASE ____________________________________________________ The values provided by HyperLEDA service are subject to periodic updates. By other hand, the morphological type is revised by the group when a new set of better images associated to a significant number of galaxies is published. A change in the value of any of these properties will affect to whole database of the study and it can mean a new release of the database. It is essential to know how different are the releases and when they are updated, so that the propagation of the changes in data values through the existing internal relation among the data will be triggered and registered. Notice the workflows belonging to this research object will not update directly the MySQL database of the study. They only produce a set of SQL scripts which can be used to update the database.