singscat: module of single scattering tools

PyHdust singscat module: Single Scatering Dumbbell+disk model.

This release contains a simplified version of the one applied to Sigma Ori E in Carciofi+2013.

Conditions: - Calculations for a given observer position: observer at z = +infinity - Single scattering by electrons (Thomson) - Star is a point-source (*or at least, a spherical emitting source) - \(\theta\) is latitude. 0 = North pole; 180 = South pole. - \(\phi\) is longitude - Spherical coordinates seguence (\(r\), \(\phi\), \(\theta\))

Remeber: - phi=0 is x direction (perpendicular to the observer) - (x, y) are not the same for (N, -E) astronomical images

license:

GNU GPL v3.0 https://github.com/danmoser/pyhdust/blob/master/LICENSE

pyhdust.singscat.angQU(Q, U, filter=True)

Calculate [Q, U] angles with filters* (avg-180 < degs > avg+180)

pyhdust.singscat.blobs_cicle(phi_ar, irad, Req=69550800000.0, rb=0.3333333333333333, db=2.0, bres=3, nb=800000000000.0)

Calculates the stokes parameters of blobsmodel over a full cycle

Parameters:

phi_ar – phi array (in rad; [0, 2pi))

pyhdust.singscat.blobs_coords(db=2, rb=0.3333333333333333, res=3, Req=1.0, phi0=0, beta=0.0)

Parameters:

• db – distance from stellar center to blob center (Req)

• rb – radius of the blob (sphere; Req)

• res – linear resolution used in the Hypercube rejection method.

• Req – stellar equatorial radius (in cm)

• phi0 – central position of the blob (in rad)

pyhdust.singscat.blobsdisk_cicle(phi_ar, irad, Req=69550800000.0, rb=0.3333333333333333, db=2.0, bres=3, nb=800000000000.0, rd=0.3333333333333333, dd=2.0, dres=11, H=0.1, beta=0.0, nd=800000000000.0, overlap=False)

Calculates the stokes parameters of blobs+disk model over a full cycle

Parameters:

phi_ar – phi array (in rad; [0, 2pi))

pyhdust.singscat.blobsdiskmodel_geo(phi0, Req=69550800000.0, rb=0.3333333333333333, db=2.0, bres=3, nb=800000000000.0, rd=0.3333333333333333, dd=2.0, dres=11, H=0.1, beta=0.0, nd=800000000000.0, overlap=False)

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Parameters:

• rb – in Req units

• overlap – disk and blob overlap each other? Default is False.

Warning: only \(\phi\) direction is checked (ie., coplanar overlap). :param beta: obliquity, in rad

pyhdust.singscat.blobsmodel_geo(phi0, Req=69550800000.0, rb=0.3333333333333333, db=2.0, bres=3, nb=800000000000.0, beta=0.0)

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Parameters:

overlap – disk and blob overlap each other? Default is False.

Warning: only \(\phi\) direction is checked (ie., coplanar overlap). :param beta: obliquity, in rad

pyhdust.singscat.calc_phase(MJDar, period, MJD0=0.0)

Calc phase [0,1)

pyhdust.singscat.cil_slice_rej(res, dd, rd)

NO z dimension

pyhdust.singscat.disk_cicle(phi_ar, irad, Req=69550800000.0, rd=0.3333333333333333, dd=2.0, dres=11, H=0.1, beta=0.0, nd=800000000000.0, radcut=[])

Calculates the stokes parameters of disk model over a full cycle

Parameters:

• phi_ar – phi array (in rad; [0, 2pi))

• radcut – vector as [[-np.pi/4, np.pi/4], [-np.pi/4+np.pi, np.pi/4+np.pi]]. [] returns a full (2*pi) disk (Radian units).

pyhdust.singscat.disk_coords(dd=2, rd=0.3333333333333333, res=11.0, Req=1.0, beta=0.0, phi0=0.0)

Cilinder slice rejection method

Parameters:

• beta – obliquity, in rad

• phi0 – only effective when beta != 0.

pyhdust.singscat.diskmodel_geo(phi0, Req=69550800000.0, rd=0.3333333333333333, dd=2.0, dres=11, H=0.1, beta=0.0, nd=800000000000.0, radcut=[])

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Parameters:

• rd – in Req units

• beta – obliquity, in rad

• radcut – vector as [[1*np.pi/4, 3*np.pi/4], [5*np.pi/4, 7*np.pi/4]]. It must be around pi/2 and 3pi/2 for phase consistency. [] returns a full (2*pi) disk (Radian units).

pyhdust.singscat.idx_phi_disklimit_coords(radcut, rd, phid, thd)

Enter the coordinates of a 2*pi disk and cuts it with the limits of radcut

Parameters:

radcut – vector as [-np.pi/6, np.pi/6]

pyhdust.singscat.loadpol(txt, old=False, p_sigP=0)

Load polarization txt file.

Parameters:

p_sigP – if > 0, filter values P/sigP

pyhdust.singscat.mod2obs(Qmod, Umod, Qis, Uis, ths)

MODEL TO OBSERV

Parameters:

• ths – theta sky in rad

• Qis – IS Q

• Uis – IS U

pyhdust.singscat.obs2mod(Qobs, Uobs, Qis, Uis, ths)

### MODEL TO OBSERV ###

Parameters:

ths – theta sky

pyhdust.singscat.plot_QU_bc(x, y, Q, U, irad, Req)

using baricenter

TODO: discover why it is not working

pyhdust.singscat.plot_QU_gd(x, y, Q, U, irad, Req)

using griddata

pyhdust.singscat.plot_coords(xb1, yb1, zb1, Req, slim=3)

Parameters:

slim – Scale limit [-slim, slim]

pyhdust.singscat.sph_hyper_rej(res)

Hypercube rejection method

pyhdust.singscat.stokes(r, phi, th, irad, dV, ne, Req, occult=True)

Parameters:

• irad – in rad

• dV – in cm3

TODO: intensity calc.

output in fraction (multiple by 100 to have percentage