# Halpha Nuclear Geyser (Bipolar Outflow) from the Barred Galaxy NGC 1415 (ESO 482-G033)

## TL;DR

This study reveals a bipolar outflow in galaxy NGC 1415 through spectroscopic analysis, identifying a nuclear geyser with velocities exceeding the galaxy's rotation, and estimates the galaxy's bar pattern speed.

## Contribution

First detection and characterization of a nuclear bipolar outflow in NGC 1415 using long slit spectroscopy and kinematic analysis.

## Key findings

- Identification of a nuclear outflow with V_outflow 140 km/s
- Outflow axis at P.A. +165 degrees, not aligned with disk rotation
- Estimated bar pattern speed Omega_{bar} = 134 km/s

## Abstract

A long slit spectrum from the barred galaxy NGC 1415 has been obtained with the 2.1m Guillermo Haro telescope in Cananea, Mexico at position angle 155d (EofN) and shows the kinematics of Na I D lines (in absorption) and Halpha, 6562.8 A, [NII] 6548 A, [NII] 6584 A, [SII] 6716 A, and [SII] 6731 A lines in emission from the central regions and the disk. Our previous Halpha continuum-free imaging of the central region showed mainly two central bright Halpha knots straddling the nucleus, and Halpha emission regions along the south-east and north-west inner spiral arms. Velocities of the Na I D absorption lines are taken as representative of the rotation curve of NGC 1415. Our kinematical data indicates that the central bright Halpha straddling the nucleus have velocities in excess of the Na I D velocities. We interpret these velocity excesses of the central bright Halpha knots as due to a geyser (nuclear bipolar outflow) with V_outflow 140 km/s at a P.A.+165d (EofN). The axis of this outflow, is not along the rotation axis of the disk of NGC 1415 (if it were, it would be at P.A.+238d (EofN)). Additionally we have determined Omega_{gas}, (radial resonances) kappa(R) and estimated the value of the pattern angular speed of an inner boxy stellar bar in NGC 1415, Omega_{bar}, from the Na I D rotation curve assuming Ratio of CR/a_{bar} = 1, Omega_{bar} = 134 km/s.