Grantecan spectroscopic observations and confirmations of planetary nebulae candidates in the Northern Galactic Plane

Abstract

We present Grantecan 10 m telescope (GTC) spectroscopic confirmations of 55 faint Planetary Nebulae (PNe) candidates discovered largely in the INT Photometric Hα Survey of the Northern Galactic Plane (IPHAS) by our pro-am collaboration. We confirm 46 of them as ‘True’ (T), 4 as ‘Likely’ (L) and 5 as ‘Possible’ (P) PNe and including 5 new PNe central star (CSPN) discoveries. This was from observations of 62 new candidates yielding a maximum PN discovery success rate of 89 per cent. The sensitivity and longer wavelength coverage of IPHAS allows PNe to be found in regions of greater extinction and at these lower Galactic latitudes, including PNe in a more advanced evolutionary state and at larger distances compared to previously known Galactic PNe. We use an holistic set of observed characteristics and optical emission-line diagnostics to confirm candidates. Plasma properties have been determined in a self-consistent way using PyNeb. This work is facilitated by the functionality of our powerful, multi-wavelength database ‘HASH’ (Hong Kong, Australian Astronomical Observatory, Strasbourg Observatory H-alpha Planetary Nebula catalogue) that federates known imaging, spectroscopy and other pertinent data for all Galactic T, L, P PNe and the significant numbers of mimics. Reddenings, corrected radial velocities and PNe electron density and temperature estimates are provided for these new PNe where possible.

Spectroscopic survey of faint planetary-nebula nuclei. I. Six new "O VI" central stars

“…DSS images show a faint (𝐺 = 19.27) blue star lying at the center, and our HET spectra are of this object. The star was also noted as a candidate WD or PNN during searches of Gaia data by Gentile Fusillo et al ( 2019) and Chornay & Walton (2020), and was identified as the central star more recently by Ritter et al (2022). Nebular spectra obtained by Acker et al (2012) and Ritter et al (2022) show strong He 4686 Å emission, implying a high temperature for the central star.…”

Planetary Nebula Morphologies Indicate a Jet-Driven Explosion of SN 1987A and Other Core-Collapse Supernovae

“…Here comes the group of bipolar PNe (i.e., those with one or more pairs of lobes). Firstly, as several PN catalogs show (e.g., Balick 1987 [5]; Chu et al 1987 [14]; Schwarz et al 1992 [62]; Corradi & Schwarz 1995 [15]; Manchado et al 1996 [37]; Sahai & Trauger1998 [60]; Hajian et al 2007 [31]; Sahai et al 2011 [59]; Parker et al 2016 [49]; Parker 2022 [48]; Ritter et al 2023 [55]; Tan et al 2023 [74]), there are over one hundred PNe that we can compare with CCSNR morphologies. Secondly, in many but not all PNe, there are direct indications of jets because the jets are long gone, and there is majority community support for the understanding that jets shaped all these bipolar PNe (e.g., Morris1987 [43]; Soker 1990 [64]; Sahai & Trauger1998 [60]; Sahai et al 2000 [58]; Sahai et al 2011 [59]; Boffin et al 2012 [9]; Fang et al 2015 [19]; Guerrero et al 2021 [30]; Moraga Baez et al 2023 [42]).…”