MeerKAT HI imaging of the jellyfish galaxy ESO 137-001

We present MeerKAT H <ns0:sc>I</ns0:sc> observations of ESO 137-001, a quintessential jellyfish galaxy with long multi-phase tails formed due to the interaction with the intra-cluster medium of its host galaxy cluster, ACO 3627. Our observations reveal the presence of H <ns0:sc>I</ns0:sc> in both the disc and outer regions of the galaxy for the first time, with a total H <ns0:sc>I</ns0:sc> mass of (3.5 ± 0.4)×108 M⊙. ESO 137-001 is at an advanced stage of gas stripping; it is extremely H <ns0:sc>I</ns0:sc> deficient and seems to have lost 90% of its initial H <ns0:sc>I</ns0:sc> mass; about 2/3 of the surviving H <ns0:sc>I</ns0:sc> is found at larger radius than expected for a normal H <ns0:sc>I</ns0:sc> disc and forms ∼40 kpc tail coincident with the tail detected at other wavelengths. Only ∼10% of the surviving H <ns0:sc>I</ns0:sc> is still found within the stellar disc, consistent with the expectation of an outside-in truncation due to ram pressure. Similarly to other jellyfish galaxies, ESO137-001 has a high star formation rate for the low amount of H <ns0:sc>I</ns0:sc> detected. We measure an H <ns0:sc>I</ns0:sc> depletion time of 0.29 Gyr. However, when taking into account the total gas (H <ns0:sc>I</ns0:sc> + H2) content, the depletion time is consistent with typical values measured in nearby spiral galaxies. This suggests that ESO 137-001 is at its current stage of ram pressure interaction characterised by an efficient H <ns0:sc>I</ns0:sc> stripping, rather than an enhanced conversion of H <ns0:sc>I</ns0:sc> to H2, which was recently observed in some other jellyfish galaxies.