Morphological classification of new candidate PNe in an IPHAS sample Kerttu Viironen IAC Collaboration: A. Mampaso (IAC) R. Corradi (ING, IAC), R. Greimel (Cambridge), L. Sabin (IAC) IPHAS collaboration

Overview: 1) PN morphology; introduction 2) IPHAS survey 3) Searching for PNe from IPHAS data 3) Morphology of the PN candidates at 18h-20h

PN morphology; introduction -PNe present various morphologies: -Elliptical, Bipolar, Point-Symmetric, Irregular, Stellar (Schwarz et al. 1992; classes author dependent) -Morphology connected to - abundances (bipolars overabundant in He, N; Corradi & Schwarz 1995) - location in Galaxy (median galactic latitude increase from bipolars to ellipticals and to rounds; Manchado & Villaver 2000) - central star properties (bipolars more massive progenitors; Corradi & Schwarz 1995) -All this should be explained theoretically; constraints the theories

IPHAS survey ING, La Palma: Corradi, Leisy, Lennon, Skillen UK: Aungwerojwit (Warwick), Barlow, Hales, Wright (UCL), Drew (PI), Unruh (Imperial), Evans (ATC), Gaensicke (Warwick), Greimel, Irwin, Walton (IoA), Knigge, Witham (Southampton), Morris, Phillipps (Bristol), Vink (Keele), Zijlstra (Manchester) Spain (IAC): Mampaso, Martin, Rodríguez-Flores, Rodríguez-Gil, Sabin, Viironen The Netherlands (Nijmegen): Groot, Morales-Rueda, van den Besselaar USA (CfA): Drake, Sokoloski & Steeghs (CfA) Australia (AAO/Macquarie): Parker Collaboration:

IPHAS survey IPHAS = the INT/WFC Photometric H  Survey of the Northern Galactic Plane Area: all l in Northern Plane; –5° < b < +5° (1800 deg 2 ) Mag. limit: ~ 20 in r’ Observations: 2.5m Isaac Newton Telescope (La Palma) + Wide Field Camera (4-CCD mosaic, 2048x4200 pix, fov 34x34 arcmin 2, 0”.33 pix -1 ) H  (120 sec), Sloan r’ (30 sec) and i’ (10 sec) at two closely overlapped pointings per field

IPHAS survey A map of the sky: IPHAS survey area shown in green

IPHAS survey Analysis: Pipeline reduction and point-source photometric and astrometric catalogue generation by CASU. IPHAS data are available immediately to astronomers from UK, Spain and the Netherlands, and to ALL astronomers after 1 year from the date of observing. IPHAS web page: IPHAS overview: Drew et al. 2005, MNRAS, 362, 753 Other IPHAS related papers: see the IPHAS webpage!

Search techniques: 1.Semi-automatic technique: photometric catalogue (r’-H  colors)  compact/small nebulae 2. visual inspection of mosaics  medium/large nebulae - There are about 2000 PNe known in the Galaxy - Several hundreds are expected to be found by IPHAS - IPHAS goes deep → faint and/or distant PNe explored The PN search Shiode et al IPHAS

The PNe search; compact PNe E(B-V)  Drew et al main sequence giants supergiants Synthetic photometry constructed using Pickles (1998) library of flux-calibrated stellar spectra r’-H  r’-i’

The PNe search; compact PNe Known PNe in IPHAS two-color diagram

The PNe search; compact PNe -Noise and saturated objects filtered out as well as the detection close to the borders of the CCDs or areas of bad pixels -Objects should be detected at least in Hα and r’ (matching distance 1 arcsec) -Object should be detected at least twice -The magnitude in Hα < 19.5

The PNe search; compact PNe Final selection made visually (so far only 18h-20h region complete!) 810 studied 613 studied, M(Hα) < 17 not studied Automatically selected objects at 18h-20h + known PNe Total: objects

The PNe search; extended PNe Visual search from IPHAS r’ – Hα mosaics: - 15 x 15 pixel binning for lowest surface brightness nebulae - 5 x 5 pixel binning for intermediate size nebulae The three methods overlap → more complete

Candidate PNe in the IPHAS area at 18h – 20h region: 389 objects found 100 of these are known PNe 289 new candidate PNe with “clear morphology” → considered in the morphological study - 37 unresolved/barely resolved)

Morphology of the PNe/PN candidates Corradi & Schwarz 1995 (359 southern PNe): Our study (133 candidate PNe in the galactic plane):

Morphology of the PNe/PN candidates Manchado & Villaver 2000 (<255 PNe in the galactic plane): Our study (133 PNe in the galactic plane):

Conclusions -IPHAS is greatly increasing the number of northern Galactic PNe -We find a new faint round PNe population in the galactic plane

Thank You!

The PNe search; compact PNe Final selection made visually 810 studied 613 studied, M(Hα) < 17 not studied Known PNe in IPHAS two-color diagram IPHAS area; 18h – 20h region